diff --git a/number/atom.go b/number/atom.go
new file mode 100644
index 0000000..2b71510
--- /dev/null
+++ b/number/atom.go
@@ -0,0 +1,502 @@
+package number
+
+import (
+	"math/big"
+
+	"gitea.zaclys.com/bvaudour/gob/option"
+)
+
+type atom struct {
+	number option.Option[*big.Rat]
+	sign   int
+}
+
+func undefined[S integer | float](sign S) atom {
+	out := atom{
+		sign: signOf(sign),
+	}
+
+	return out.format()
+}
+
+func rational[S integer | float](rat *big.Rat, sign ...S) atom {
+	s := 1
+	if len(sign) > 0 {
+		s = signOf(sign[0])
+	}
+
+	out := atom{
+		number: option.Some(rat),
+		sign:   s,
+	}
+
+	return out.format()
+}
+
+func frac0[S integer | float](num, denom *big.Int, sign ...S) atom {
+	if denom.IsInt64() && denom.Int64() == 0 {
+		s := num.Sign()
+		if len(sign) > 0 {
+			s *= signOf(sign[0])
+		}
+		return undefined(s)
+	}
+
+	rat := new(big.Rat).SetFrac(num, denom)
+	return rational(rat, sign...)
+}
+
+func frac[N integer | float, S integer | float](num, denom N, sign ...S) atom {
+	if denom == 0 {
+		s := signOf(num)
+		if len(sign) > 0 {
+			s *= signOf(sign[0])
+		}
+		return undefined(s)
+	}
+
+	rat := new(big.Rat).SetFrac64(int64(num), int64(denom))
+	return rational(rat, sign...)
+}
+
+func entire0[S integer | float](n *big.Int, sign ...S) atom {
+	rat := new(big.Rat).SetInt(n)
+
+	return rational(rat, sign...)
+}
+
+func entire[N integer | float, S integer | float](n N, sign ...S) atom {
+	rat := new(big.Rat).SetInt64(int64(n))
+
+	return rational(rat, sign...)
+}
+
+func decimal[N integer | float, S integer | float](n N, sign ...S) atom {
+	rat := new(big.Rat).SetFloat64(float64(n))
+
+	return rational(rat, sign...)
+}
+
+func pow[B integer | float, P integer | float](base B, precision ...P) atom {
+	p := FloatingPrecision
+	if len(precision) > 0 {
+		p = uint64(precision[0])
+	}
+
+	a := entire(formatBase(base), 1)
+	return a.pow(p)
+}
+
+func (a atom) get() (*big.Rat, bool) {
+	return a.number.Get()
+}
+
+func (a *atom) format() atom {
+	if nb, ok := a.get(); ok {
+		a.sign *= nb.Sign()
+		nb.Abs(nb)
+	}
+
+	a.sign = signOf(a.sign)
+	return *a
+}
+
+func (a atom) clone(format ...bool) atom {
+	out := atom{
+		sign: a.sign,
+	}
+	if nb, ok := a.get(); ok {
+		out.number = option.Some(new(big.Rat).Set(nb))
+	}
+
+	if len(format) > 0 && format[0] {
+		return out.format()
+	}
+	return out
+}
+
+func (a atom) rat() (nb *big.Rat, ok bool) {
+	if nb, ok = a.get(); ok {
+		nb = new(big.Rat).Set(nb)
+		if a.sign < 0 {
+			nb.Neg(nb)
+		} else if a.sign == 0 {
+			nb.SetInt64(0)
+		}
+	}
+
+	return
+}
+
+func (a atom) Sign() int {
+	return a.sign
+}
+
+func (a atom) IsNeg() bool {
+	return a.Sign() < 0
+}
+
+func (a atom) IsPos() bool {
+	return !a.IsNeg()
+}
+
+func (a atom) IsZero() bool {
+	return a.Is(0)
+}
+
+func (a atom) neg() atom {
+	out := a.clone()
+	out.sign = -out.sign
+
+	return out.format()
+}
+
+func (a atom) abs() atom {
+	out := a.clone()
+	if out.sign < 0 {
+		out.sign = -out.sign
+	}
+
+	return out.format()
+}
+
+func (a atom) IsDefined() bool {
+	return a.number.IsDefined()
+}
+
+func (a atom) IsInf() bool {
+	return !a.IsDefined() && a.Sign() > 0
+}
+
+func (a atom) IsNegInf() bool {
+	return !a.IsDefined() && a.Sign() < 0
+}
+
+func (a atom) IsNan() bool {
+	return !a.IsDefined() && a.Sign() == 0
+}
+
+func (a atom) Is(i int64) bool {
+	if nb, ok := a.get(); ok {
+		return nb.IsInt() && nb.Num().Int64()*int64(a.Sign()) == i
+	}
+
+	return false
+}
+
+func (a atom) IsFloat(f float64) bool {
+	if nb, ok := a.get(); ok {
+		e, ok := nb.Float64()
+		return ok && e*float64(a.Sign()) == f
+	}
+
+	return false
+}
+
+func (a atom) isInt() bool {
+	if nb, ok := a.get(); ok {
+		return nb.IsInt()
+	}
+
+	return false
+}
+
+func (a atom) isInt64() bool {
+	if nb, ok := a.get(); ok {
+		return nb.IsInt() && nb.Num().IsInt64()
+	}
+	return false
+}
+
+func (a atom) toInt64() (n int64, ok bool) {
+	var nb *big.Rat
+	if nb, ok = a.get(); ok {
+		if nb.IsInt() {
+			if num := nb.Num(); num.IsInt64() {
+				n = num.Int64()
+			}
+		}
+	}
+
+	return
+}
+
+func (a *atom) setInt() atom {
+	if nb, ok := a.get(); ok {
+		nb.SetInt(new(big.Int).Quo(nb.Num(), nb.Denom()))
+	}
+
+	return a.format()
+}
+
+func (a atom) num() atom {
+	if a.Sign() == 0 {
+		return entire(0, 0)
+	} else if nb, ok := a.get(); ok {
+		return entire0(nb.Num(), a.Sign())
+	}
+
+	return entire(a.Sign(), 1)
+}
+
+func (a atom) denom() atom {
+	if nb, ok := a.get(); ok {
+		return entire0(nb.Denom(), 1)
+	}
+
+	return entire(0, 0)
+}
+
+func (a1 atom) cmp(a2 atom) int {
+	if a1.IsNan() {
+		if a2.IsNan() {
+			return 0
+		}
+		return -2
+	} else if a2.IsNan() {
+		return 2
+	} else if nb1, ok := a1.rat(); ok {
+		if nb2, ok := a2.rat(); ok {
+			return nb1.Cmp(nb2)
+		}
+		return -a2.Sign()
+	} else if a2.IsDefined() {
+		return a1.Sign()
+	}
+
+	return compare(a1.Sign(), a2.Sign())
+}
+
+func (a1 atom) add(a2 atom) atom {
+	if r1, ok := a1.rat(); ok {
+		if r2, ok := a2.rat(); ok {
+			return rational(new(big.Rat).Add(r1, r2), 1)
+		}
+		return a2.clone()
+	} else if a2.IsDefined() || a1.Sign() == a2.Sign() {
+		return undefined(a1.Sign())
+	}
+
+	return undefined(0)
+}
+
+func (a1 atom) sub(a2 atom) atom {
+	return a1.add(a2.neg())
+}
+
+func (a atom) inc() atom {
+	return a.add(entire(1, 1))
+}
+
+func (a atom) dec() atom {
+	return a.sub(entire(1, 1))
+}
+
+func (a1 atom) mul(a2 atom) atom {
+	s := a1.Sign() * a2.Sign()
+	if nb1, ok := a1.get(); ok {
+		if nb2, ok := a2.get(); ok {
+			return rational(new(big.Rat).Mul(nb1, nb2), s)
+		}
+	}
+
+	return undefined(s)
+}
+
+func (a1 atom) div(a2 atom) atom {
+	if nb1, ok := a1.get(); ok {
+		if nb2, ok := a2.get(); ok {
+			if nb2.IsInt() && nb2.Num().IsInt64() && nb2.Num().Int64() == 0 {
+				return undefined(0)
+			}
+			return rational(new(big.Rat).Quo(nb1, nb2), a1.Sign()*a2.Sign())
+		}
+		return undefined(a1.Sign() * a2.Sign())
+	} else if a2.IsDefined() {
+		return undefined(a1.Sign() * a2.Sign())
+	}
+
+	return undefined(0)
+}
+
+func (a1 atom) quo(a2 atom) atom {
+	if nb1, ok := a1.get(); ok {
+		if nb2, ok := a2.get(); ok {
+			if nb2.IsInt() && nb2.Num().IsInt64() && nb2.Num().Int64() == 0 {
+				return undefined(0)
+			}
+			n := new(big.Int).Mul(nb1.Num(), nb2.Num())
+			d := new(big.Int).Mul(nb1.Denom(), nb2.Denom())
+			return entire0(new(big.Int).Quo(n, d), a1.Sign()*a2.Sign())
+		}
+		return undefined(a1.Sign() * a2.Sign())
+	} else if a2.IsDefined() {
+		return undefined(a1.Sign() * a2.Sign())
+	}
+
+	return undefined(0)
+}
+
+func (a1 atom) quoRem(a2 atom) (q, r atom) {
+	q = a1.quo(a2)
+	r = a1.sub(a2.mul(q))
+
+	return
+}
+
+func (a1 atom) rem(a2 atom) atom {
+	_, r := a1.quoRem(a2)
+	return r
+}
+
+func (a atom) inv() atom {
+	if nb, ok := a.get(); ok {
+		n, d := nb.Num(), nb.Denom()
+		return frac0(d, n, a.Sign())
+	}
+
+	if a.Sign() == 0 {
+		return undefined(0)
+	}
+	return entire(0, 0)
+}
+
+func (a atom) pow(p uint64) atom {
+	switch {
+	case p == 0:
+		if a.IsNan() {
+			return undefined(0)
+		}
+		return entire(0, 0)
+	case p == 1:
+		return a.clone(true)
+	case p == 2:
+		return a.mul(a)
+	case p&1 == 0:
+		return a.mul(a).pow(p >> 1)
+	default:
+		return a.mul(a).pow(p >> 1).mul(a)
+	}
+}
+
+func (a atom) optimize(precision atom) atom {
+	if a.isInt() || !a.IsDefined() {
+		return a
+	}
+
+	n1, d1 := a.num().abs(), a.denom()
+	t := n1.mul(precision).quo(d1)
+	an := t.div(precision)
+	n2, d2 := an.num(), an.denom()
+	if n2.cmp(n1) < 0 || d2.cmp(d1) < 0 {
+		t.sign = a.sign
+		return t.format()
+	}
+
+	return a
+}
+
+func (a atom) heron(n uint64, tmp atom) atom {
+	n0 := entire(int64(n), 1)
+	n1 := n0.dec()
+
+	return ((tmp.mul(n1)).add(a.div(tmp.pow(n - 1)))).div(n0)
+}
+
+func (a atom) sqrtn(n uint64, base uint) atom {
+	switch {
+	case a.IsNan() || n < 2 || (a.IsNeg() && n&1 == 0):
+		return undefined(0)
+	case a.IsZero() || a.Is(1) || !a.IsDefined():
+		return a.clone(true)
+	default:
+		precision := pow(base, FloatingPrecision)
+		pi := precision.inv()
+		out := a.heron(n, a).optimize(precision)
+		for {
+			t := a.heron(n, out).optimize(precision)
+			if out.cmp(t) == 0 {
+				break
+			} else if out.sub(t).abs().cmp(pi) < 0 {
+				out = t
+				break
+			}
+		}
+
+		return out
+	}
+}
+
+func (a atom) IsEven() bool {
+	if nb, ok := a.get(); ok {
+		return nb.IsInt() && nb.Num().Bit(0) == 0
+	}
+
+	return false
+}
+
+func (a atom) IsOdd() bool {
+	if nb, ok := a.get(); ok {
+		return nb.IsInt() && nb.Num().Bit(0) != 0
+	}
+
+	return false
+}
+
+func (a atom) lsh(n uint) atom {
+	if nb, ok := a.get(); ok {
+		if nb.IsInt() {
+			num, denom := new(big.Int).Lsh(nb.Num(), n), nb.Denom()
+			return frac0(num, denom, a.Sign())
+		}
+		return a.mul(pow(2, n))
+	}
+
+	return undefined(a.Sign())
+}
+
+func (a atom) rsh(n uint) atom {
+	if nb, ok := a.get(); ok {
+		if nb.IsInt() {
+			num, denom := new(big.Int).Rsh(nb.Num(), n), nb.Denom()
+			return frac0(num, denom, a.Sign())
+		}
+		return a.div(pow(2, n))
+	}
+
+	return undefined(a.Sign())
+}
+
+func (a atom) len(base uint) int {
+	if nb, ok := a.get(); ok {
+		if !nb.IsInt() {
+			return -1
+		}
+		num := nb.Num()
+		if num.IsInt64() && num.Int64() == 0 {
+			return 1
+		}
+		s := num.Text(int(base))
+		return len(s)
+	}
+
+	return -1
+}
+
+func (a atom) bit(n uint64, base uint) int {
+	if !a.isInt() {
+		return -1
+	}
+
+	out := a
+	if n > 0 {
+		out = a.quo(pow(base, n))
+	}
+
+	out = out.rem(entire(base, 1))
+	if nb, ok := out.get(); ok {
+		return int(nb.Num().Int64())
+	}
+
+	return -1
+}
diff --git a/number/const.go b/number/const.go
new file mode 100644
index 0000000..9ad31da
--- /dev/null
+++ b/number/const.go
@@ -0,0 +1,48 @@
+package number
+
+import (
+	"fmt"
+	"regexp"
+)
+
+var (
+	FloatingPrecision uint64 = 10    // Nombre de chiffres après la virgule pour un nombre décimal ou un nombre scientifique
+	FixedPrecision           = false // Si vrai le nombre chiffre après la virgule est fixe.
+)
+
+const (
+	regSign   = `\+|-`
+	regBSign  = `0|1`
+	regBase   = `\(\d+\)`
+	regBase2  = `B|b`
+	regBase8  = `O|o`
+	regBase16 = `X|x`
+	regNb     = `[0-9a-zA-Z]`
+	regNb2    = `0|1`
+	regNb8    = `[0-7]`
+	regNb10   = `\d`
+	regNb16   = `[0-9a-fA-F]`
+	regExp    = `×\d+\^`
+	regExp10  = `E|e`
+)
+
+var (
+	regInt   = regexp.MustCompile(fmt.Sprintf(`%s(%s)?%s+`, regBase, regSign, regNb))
+	regInt2  = regexp.MustCompile(fmt.Sprintf(`(%s)(%s)(%s)+`, regBSign, regBase2, regNb2))
+	regInt8  = regexp.MustCompile(fmt.Sprintf(`(%s)(%s)(%s)+`, regBSign, regBase8, regNb8))
+	regInt10 = regexp.MustCompile(fmt.Sprintf(`(%s)?%s+`, regSign, regNb10))
+	regInt16 = regexp.MustCompile(fmt.Sprintf(`(%s)(%s)(%s)+`, regBSign, regBase16, regNb16))
+
+	regDec   = regexp.MustCompile(fmt.Sprintf(`%s(%s)?(%s*\.%s+|%s+\.)`, regBase, regSign, regNb, regNb, regNb))
+	regDec2  = regexp.MustCompile(fmt.Sprintf(`(%s)(%s)((%s)*\.(%s)+|(%s)+\.)`, regBSign, regBase2, regNb2, regNb2, regNb2))
+	regDec8  = regexp.MustCompile(fmt.Sprintf(`(%s)(%s)((%s)*\.(%s)+|(%s)+\.)`, regBSign, regBase8, regNb8, regNb8, regNb8))
+	regDec10 = regexp.MustCompile(fmt.Sprintf(`(%s)?(%s*\.%s+|%s+\.)`, regSign, regNb10, regNb10, regNb10))
+	regDec16 = regexp.MustCompile(fmt.Sprintf(`(%s)(%s)((%s)*\.(%s)+|(%s)+\.)`, regBSign, regBase16, regNb16, regNb16, regNb16))
+
+	regFrac   = regexp.MustCompile(fmt.Sprintf(`%s(%s)?%s+/(%s)?%s+`, regBase, regSign, regNb, regSign, regNb))
+	regFrac10 = regexp.MustCompile(fmt.Sprintf(`(%s)?%s+/(%s)?%s+`, regSign, regNb10, regSign, regNb10))
+
+	regSci         = regexp.MustCompile(fmt.Sprintf(`%s(%s)?(%s*\.%s+|%s+\.?)%s(%s)?(%s)+`, regBase, regSign, regNb, regNb, regNb, regExp, regSign, regNb10))
+	regSci10Simple = regexp.MustCompile(fmt.Sprintf(`%s(%s)?(%s*\.%s+|%s+\.?)`, regSign, regNb10, regNb10, regNb10, regExp, regSign, regNb10))
+	regSci10       = regexp.MustCompile(fmt.Sprintf(`%s(%s)?(%s*\.%s+|%s+\.?)`, regSign, regNb10, regNb10, regNb10, regExp10, regSign, regNb10))
+)
diff --git a/number/convert.go b/number/convert.go
new file mode 100644
index 0000000..9b7c44d
--- /dev/null
+++ b/number/convert.go
@@ -0,0 +1,486 @@
+package number
+
+import (
+	"fmt"
+	"math/big"
+	"strconv"
+	"strings"
+
+	"gitea.zaclys.com/bvaudour/gob/option"
+)
+
+func undefinedString(sign int) string {
+	switch sign {
+	case -1:
+		return "-∞"
+	case +1:
+		return "+∞"
+	default:
+		return "NaN"
+	}
+}
+
+func integerString(n *big.Int, base uint, sign int) string {
+	out := n.Text(int(base))
+
+	if sign < 0 {
+		out = fmt.Sprintf("-%s", out)
+	}
+
+	if base != 10 {
+		out = fmt.Sprintf("(%d)%s", base, out)
+	}
+
+	return out
+}
+
+func fractionString(n, d *big.Int, base uint, sign int) string {
+	out := fmt.Sprintf("%s/%s", n.Text(int(base)), d.Text(int(base)))
+
+	if sign < 0 {
+		out = fmt.Sprintf("-%s", out)
+	}
+
+	if base != 10 {
+		out = fmt.Sprintf("(%d)%s", base, out)
+	}
+
+	return out
+}
+
+func decimalString(n Number) string {
+	base := n.Base()
+	num, denom := n.num(), n.denom()
+	p := pow(base, FloatingPrecision)
+	num = num.mul(p)
+	q := num.quo(denom)
+
+	out := "0"
+	if num.cmp(denom) >= 0 {
+		if qn, ok := q.get(); ok {
+			out = qn.Num().Text(int(base))
+		} else {
+			return ""
+		}
+	}
+
+	precision := int(FloatingPrecision)
+	if len(out) < precision {
+		out = fmt.Sprintf("%s%s", strings.Repeat("0", precision), out)
+	}
+
+	deltaPrecision := len(out) - precision
+	out = fmt.Sprintf("%s.%s", out[:deltaPrecision], out[deltaPrecision:])
+
+	if !FixedPrecision {
+		l := len(out) - 1
+		for out[l] == '0' {
+			out, l = out[:l], l-1
+		}
+		if out == "." {
+			out = "0."
+		}
+	}
+
+	if n.IsNeg() {
+		out = fmt.Sprintf("-%s", out)
+	} else if q.IsZero() && !n.IsZero() {
+		out = fmt.Sprintf("+%s", out)
+	}
+
+	if base != 10 {
+		out = fmt.Sprintf("(%d)%s", base, out)
+	}
+
+	return out
+}
+
+func scientificStsring(n Number) string {
+	base := n.Base()
+	var exponent int
+	tmp := n
+	if n.IsZero() {
+		num, denom := n.Abs().NumDenom()
+		nl, dl := num.Len(), denom.Len()
+		exponent := nl - dl
+		if exponent > 0 {
+			denom = denom.Mul(Number{
+				base: base,
+				tpe:  Integer,
+				atom: pow(base, exponent),
+			})
+		} else if exponent < 0 {
+			num = num.Mul(Number{
+				base: base,
+				tpe:  Integer,
+				atom: pow(base, -exponent),
+			})
+		}
+
+		if num.Lt(denom) {
+			exponent--
+			num.Mul(Int(base, base))
+		}
+		tmp = num.Div(denom)
+	}
+
+	out := decimalString(tmp)
+
+	signExponent := ""
+	if exponent > 0 {
+		signExponent = "+"
+	} else if exponent < 0 {
+		signExponent = "-"
+	}
+
+	if base == 10 {
+		return fmt.Sprintf("%sE%s%d", out, signExponent, exponent)
+	}
+	return fmt.Sprintf("%s×%d^%s%d", out, base, signExponent, exponent)
+}
+
+// String retourne la représentation du nombre sous forme de chaîne de caractères.
+func (n Number) String() string {
+	if nb, ok := n.get(); ok {
+		switch n.Type() {
+		case Integer:
+			return integerString(nb.Num(), n.Base(), n.Sign())
+		case Fraction:
+			return fractionString(nb.Num(), nb.Denom(), n.base, n.Sign())
+		case Scientific:
+			return scientificStsring(n)
+		default:
+			return decimalString(n)
+		}
+	}
+
+	return undefinedString(n.Sign())
+}
+
+func parseBase(str string) (next string, base option.Option[uint]) {
+	begin := strings.Index(str, "(")
+	end := strings.Index(str, ")")
+	if begin > end || begin < 0 || end < 0 {
+		return
+	}
+
+	next = str[end+1:]
+	if b, err := strconv.ParseUint(str[begin+1:end], 10, 64); err == nil && isBaseValid(b) {
+		base = option.Some(uint(b))
+	}
+	return
+}
+
+func parseBaseN(str string) (next string, base uint) {
+	next = str[1:]
+	switch str[0] {
+	case 'B', 'b':
+		base = 2
+	case 'O', 'o':
+		base = 8
+	default:
+		base = 16
+	}
+
+	return
+}
+
+func parseSign(str string) (next string, sign int) {
+	switch str[0] {
+	case '-':
+		next, sign = str[1:], -1
+	case '+':
+		next, sign = str[1:], 1
+	default:
+		next, sign = str, 1
+	}
+
+	return
+}
+
+func parseSignN(str string) (next string, sign int) {
+	next, sign = str[1:], 1
+	if str[0] == '1' {
+		sign = -1
+	}
+
+	return
+}
+
+func parseNumber(str string, base uint) (n option.Option[*big.Int]) {
+	if e, ok := new(big.Int).SetString(str, int(base)); ok {
+		n = option.Some(e)
+	}
+
+	return
+}
+
+func setInt(str string, base uint, sign int) (n option.Option[Number]) {
+	if nb, ok := parseNumber(str, base).Get(); ok {
+		nn := Number{
+			base: base,
+			tpe:  Integer,
+			atom: entire0(nb, sign),
+		}
+		n = option.Some(nn.format())
+	}
+
+	return
+}
+
+func parseInt(str string) (n option.Option[Number]) {
+	next, base := parseBase(str)
+
+	if b, ok := base.Get(); ok {
+		next, sign := parseSign(next)
+		n = setInt(next, b, sign)
+	}
+
+	return
+}
+
+func parseInt10(str string) (n option.Option[Number]) {
+	next, sign := parseSign(str)
+
+	return setInt(next, 10, sign)
+}
+
+func parseIntN(str string) (n option.Option[Number]) {
+	next, sign := parseSignN(str)
+	next, base := parseBaseN(next)
+
+	return setInt(next, base, sign)
+}
+
+func setFrac(str string, base uint, sign int) (n option.Option[Number]) {
+	i := strings.Index(str, "/")
+	if i < 0 {
+		return
+	}
+
+	sNum, sDenom := str[:i], str[i:]
+	if num, ok := parseNumber(sNum, base).Get(); ok {
+		if denom, ok := parseNumber(sDenom, base).Get(); ok {
+			nn := Number{
+				base: base,
+				tpe:  Fraction,
+				atom: frac0(num, denom, sign),
+			}
+			n = option.Some(nn.format())
+		}
+	}
+
+	return
+}
+
+func parseFrac(str string) (n option.Option[Number]) {
+	next, base := parseBase(str)
+
+	if b, ok := base.Get(); ok {
+		next, sign := parseSign(next)
+		n = setFrac(next, b, sign)
+	}
+
+	return
+}
+
+func parseFrac10(str string) (n option.Option[Number]) {
+	next, sign := parseSign(str)
+
+	return setFrac(next, 10, sign)
+}
+
+func parseDot(str string) (next string, dot int) {
+	i := strings.Index(str, ".")
+	if i >= 0 {
+		next = str[:i] + str[:i]
+		dot = len(next) - i
+	}
+
+	return
+}
+
+func setDec(str string, base uint, sign int) (n option.Option[Number]) {
+	next, dot := parseDot(str)
+
+	if num, ok := parseNumber(next, base).Get(); ok {
+		denom := pow(base, dot)
+		nn := Number{
+			base: base,
+			tpe:  Decimal,
+			atom: entire0(num, sign).div(denom),
+		}
+		n = option.Some(nn.format())
+	}
+
+	return
+}
+
+func parseDec(str string) (n option.Option[Number]) {
+	next, base := parseBase(str)
+
+	if b, ok := base.Get(); ok {
+		next, sign := parseSign(next)
+		n = setDec(next, b, sign)
+	}
+
+	return
+}
+
+func parseDec10(str string) (n option.Option[Number]) {
+	next, sign := parseSign(str)
+
+	return setDec(next, 10, sign)
+}
+
+func parseDecN(str string) (n option.Option[Number]) {
+	next, sign := parseSignN(str)
+	next, base := parseBaseN(next)
+
+	return setDec(next, base, sign)
+}
+
+func parseExp(str string) (next string, baseExponent option.Option[int], exponent option.Option[int]) {
+	begin := strings.Index(str, "x")
+	end := strings.Index(str, "^")
+	if begin > end || begin < 0 || end < 0 {
+		return
+	}
+
+	sBase, sExponent := str[begin+1:end], str[end+1:]
+
+	if b, err := strconv.Atoi(sBase); err == nil && isBaseValid(b) {
+		if e, err := strconv.Atoi(sExponent); err == nil {
+			next, baseExponent, exponent = str[:begin], option.Some(b), option.Some(e)
+		}
+	}
+
+	return
+}
+
+func parseExp10(str string) (next string, exponent option.Option[int]) {
+	i := strings.Index(strings.ToLower(str), "e")
+	if i < 0 {
+		return
+	}
+
+	sExponent := str[i+1:]
+
+	if e, err := strconv.Atoi(sExponent); err == nil {
+		next, exponent = str[:i], option.Some(e)
+	}
+
+	return
+}
+
+func setSci(str string, base uint, sign, baseExponent, exponent int) (n option.Option[Number]) {
+	next, dot := parseDot(str)
+
+	if num, ok := parseNumber(next, base).Get(); ok {
+		denom := pow(base, dot)
+		nn := Number{
+			base: base,
+			tpe:  Scientific,
+			atom: entire0(num, sign).div(denom),
+		}
+		if exponent > 0 {
+			nn.atom = nn.atom.mul(pow(baseExponent, exponent))
+		} else if exponent < 0 {
+			nn.atom = nn.atom.div(pow(baseExponent, -exponent))
+		}
+
+		n = option.Some(nn.format())
+	}
+
+	return
+}
+
+func parseSci(str string) (n option.Option[Number]) {
+	next, base := parseBase(str)
+
+	if b, ok := base.Get(); ok {
+		next, sign := parseSign(next)
+		next, be, e := parseExp(next)
+		if baseExponent, ok := be.Get(); ok {
+			if exponent, ok := e.Get(); ok {
+				n = setSci(next, b, sign, baseExponent, exponent)
+			}
+		}
+	}
+
+	return
+}
+
+func parseSci10(str string) (n option.Option[Number]) {
+	next, sign := parseSign(str)
+	next, be, e := parseExp(next)
+
+	if baseExponent, ok := be.Get(); ok {
+		if exponent, ok := e.Get(); ok {
+			n = setSci(next, 10, sign, baseExponent, exponent)
+		}
+	}
+
+	return
+}
+
+func parseSci10Simple(str string) (n option.Option[Number]) {
+	next, sign := parseSign(str)
+	next, e := parseExp10(next)
+
+	if exponent, ok := e.Get(); ok {
+		n = setSci(next, 10, sign, 10, exponent)
+	}
+
+	return
+}
+
+// Parse retourne un nombre à partir d’une chaîne de caractères.
+func Parse(str string) option.Option[Number] {
+	switch str {
+	case "+∞", "<inf>", "<+inf>":
+		return option.Some(Inf())
+	case "-∞", "<-inf>":
+		return option.Some(NegInf())
+	case "NaN", "<NaN>":
+		return option.Some(Nan())
+	}
+
+	switch {
+	case regInt.MatchString(str):
+		return parseInt(str)
+	case regInt10.MatchString(str):
+		return parseInt10(str)
+	case regInt2.MatchString(str), regInt8.MatchString(str), regInt16.MatchString(str):
+		return parseIntN(str)
+	case regFrac.MatchString(str):
+		return parseFrac(str)
+	case regFrac10.MatchString(str):
+		return parseFrac10(str)
+	case regDec.MatchString(str):
+		return parseInt(str)
+	case regDec10.MatchString(str):
+		return parseInt10(str)
+	case regDec2.MatchString(str), regDec8.MatchString(str), regDec16.MatchString(str):
+		return parseIntN(str)
+	case regSci.MatchString(str):
+		return parseSci(str)
+	case regSci10.MatchString(str):
+		return parseSci10(str)
+	case regSci10Simple.MatchString(str):
+		return parseSci10Simple(str)
+	}
+
+	return option.None[Number]()
+}
+
+func ParseBool(b bool) Number {
+	if b {
+		return One()
+	}
+	return Zero()
+}
+
+func ToBool(n Number) bool {
+	return !n.IsZero() && !n.IsNan()
+}
diff --git a/number/number.go b/number/number.go
new file mode 100644
index 0000000..fde7a9b
--- /dev/null
+++ b/number/number.go
@@ -0,0 +1,426 @@
+package number
+
+// NumberType représente le type d’un nombre.
+type NumberType uint
+
+const (
+	Integer NumberType = iota
+	Scientific
+	Decimal
+	Fraction
+)
+
+// Number représente un nombre.
+type Number struct {
+	atom
+	tpe  NumberType
+	base uint
+}
+
+// Undefined retourne un nombre indéfini, signé :
+// - si sign < 0, retourne -∞
+// - si sign > 0, retourne +∞
+// - sinon, retourne NaN
+func Undefined(sign int) Number {
+	return Number{
+		base: 10,
+		tpe:  Integer,
+		atom: undefined(sign),
+	}
+}
+
+// Nan retourne NaN.
+func Nan() Number { return Undefined(0) }
+
+// Inf retourne +∞.
+func Inf() Number { return Undefined(1) }
+
+// NegInf retourne -∞.
+func NegInf() Number { return Undefined(-1) }
+
+// Int retourne un nombre à partir d’un entier, et éventuellement une base.
+func Int[N integer](n N, base ...uint) Number {
+	return Number{
+		base: formatBase(base...),
+		tpe:  Integer,
+		atom: entire(n, 1),
+	}
+}
+
+// Zero retourne le nombre 0.
+func Zero(base ...uint) Number { return Int(0, base...) }
+
+// One retourne le nombre 1.
+func One(base ...uint) Number { return Int(1, base...) }
+
+// Two retourne le nombre 2.
+func Two(base ...uint) Number { return Int(2, base...) }
+
+// Float retourne un nombre à partir d’un flottant, et éventuellement, une base.
+func Float[N ~float32 | ~float64](n N, base ...uint) Number {
+	return Number{
+		base: formatBase(base...),
+		tpe:  Decimal,
+		atom: decimal(n, 1),
+	}
+}
+
+// Frac retourne un nombre à partir du numérateur, du dénominateur, et éventuellement, une base.
+func Frac[N integer](num N, denom N, base ...uint) Number {
+	return Number{
+		base: formatBase(base...),
+		tpe:  Fraction,
+		atom: frac(num, denom, 1),
+	}
+}
+
+func (n Number) set(a atom, format ...bool) Number {
+	out := Number{
+		atom: a,
+		tpe:  n.tpe,
+		base: n.base,
+	}
+
+	return out.format(format...)
+}
+
+func (n *Number) format(formatAtom ...bool) Number {
+	if len(formatAtom) > 0 && formatAtom[0] {
+		n.atom.format()
+	}
+
+	n.base = formatBase(n.base)
+
+	if !n.IsDefined() {
+		n.base = 10
+		n.tpe = Integer
+	} else if n.tpe == Integer && !n.isInt() {
+		n.setInt()
+	}
+
+	return *n
+}
+
+func (n Number) clone(format ...bool) Number {
+	out := Number{
+		atom: n.atom.clone(format...),
+		tpe:  n.tpe,
+		base: n.base,
+	}
+
+	if len(format) > 0 && format[0] {
+		return out.format()
+	}
+	return out
+}
+
+// Type retourne le type de nombre.
+func (n Number) Type() NumberType {
+	return n.tpe
+}
+
+// ToType convertit le nombre au type donné.
+func (n Number) ToType(t NumberType) Number {
+	out := n.clone()
+	switch t {
+	case Integer, Decimal, Fraction, Scientific:
+		out.tpe = t
+	default:
+		out.tpe = Decimal
+	}
+
+	return out.format(true)
+}
+
+// Base retourne la base du nombre.
+func (n Number) Base() uint {
+	return n.base
+}
+
+// ToBase convertit le nombre dans la base donnée.
+func (n Number) ToBase(base uint) Number {
+	out := n.clone(true)
+	out.base = formatBase(base)
+
+	return out
+}
+
+// Neg retourne -n.
+func (n Number) Neg() Number {
+	return n.set(n.neg())
+}
+
+// Abs retourne |n|.
+func (n Number) Abs() Number {
+	return n.set(n.abs())
+}
+
+// IsInt retourne vrai si le nombre est entier.
+func (n Number) IsInt() bool {
+	return n.isInt()
+}
+
+// Num retourne le numérateur.
+func (n Number) Num() Number {
+	out := Number{
+		atom: n.num(),
+		base: n.base,
+		tpe:  Integer,
+	}
+
+	return out.format()
+}
+
+// Denom retourne le dénominateur.
+func (n Number) Denom() Number {
+	out := Number{
+		atom: n.denom(),
+		base: n.base,
+		tpe:  Integer,
+	}
+
+	return out.format()
+}
+
+// Num retourne le numérateur et le dénominateur.
+func (n Number) NumDenom() (Number, Number) {
+	return n.Num(), n.Denom()
+}
+
+// Cmp retourne :
+// - -1 si n1 < n2
+// - +1 si n1 > n2
+// - 0 sinon.
+func (n1 Number) Cmp(n2 Number) int {
+	return n1.cmp(n2.atom)
+}
+
+func (n1 Number) Eq(n2 Number) bool { return n1.Cmp(n2) == 0 }
+func (n1 Number) Ne(n2 Number) bool { return n1.Cmp(n2) != 0 }
+func (n1 Number) Gt(n2 Number) bool { return n1.Cmp(n2) > 0 }
+func (n1 Number) Lt(n2 Number) bool { return n1.Cmp(n2) < 0 }
+func (n1 Number) Ge(n2 Number) bool { return n1.Cmp(n2) >= 0 }
+func (n1 Number) Le(n2 Number) bool { return n1.Cmp(n2) <= 0 }
+
+// Add retourne n1 + n2.
+func (n1 Number) Add(n2 Number) Number {
+	out := Number{
+		base: n1.base,
+		tpe:  max(n1.tpe, n2.tpe),
+		atom: n1.add(n2.atom),
+	}
+
+	return out.format()
+}
+
+// Sub retourne n1 - n2.
+func (n1 Number) Sub(n2 Number) Number {
+	out := Number{
+		base: n1.base,
+		tpe:  max(n1.tpe, n2.tpe),
+		atom: n1.sub(n2.atom),
+	}
+
+	return out.format()
+}
+
+// Inc retourne n + 1.
+func (n Number) Inc() Number {
+	return n.Add(One())
+}
+
+// Dec retourne n − 1.
+func (n Number) Dec() Number {
+	return n.Sub(One())
+}
+
+// Mul retourne n1 × n2.
+func (n1 Number) Mul(n2 Number) Number {
+	out := Number{
+		base: n1.base,
+		tpe:  max(n1.tpe, n2.tpe),
+		atom: n1.mul(n2.atom),
+	}
+
+	return out.format()
+}
+
+// Div retourne n1 ÷ n2 (division exacte).
+func (n1 Number) Div(n2 Number) Number {
+	out := Number{
+		base: n1.base,
+		tpe:  max(n1.tpe, n2.tpe),
+		atom: n1.div(n2.atom),
+	}
+
+	return out.format()
+}
+
+// Quo retourne n1 ÷ n2 (division entière).
+func (n1 Number) Quo(n2 Number) Number {
+	out := Number{
+		base: n1.base,
+		tpe:  Integer,
+		atom: n1.quo(n2.atom),
+	}
+
+	return out.format()
+}
+
+// Rem retourne n1 % n2.
+func (n1 Number) Rem(n2 Number) Number {
+	out := Number{
+		base: n1.base,
+		tpe:  max(n1.tpe, n2.tpe),
+		atom: n1.rem(n2.atom),
+	}
+
+	return out.format()
+}
+
+// QuoRem retourne la division entière et le reste.
+func (n1 Number) QuoRem(n2 Number) (q, r Number) {
+	q.base, r.base = n1.base, n1.base
+	q.tpe, r.tpe = Integer, max(n1.tpe, n2.tpe)
+	q.atom, r.atom = n1.quoRem(n2.atom)
+
+	return q.format(), r.format()
+}
+
+// Inv retourne 1 ÷ n.
+func (n Number) Inv() Number {
+	t := n.tpe
+	if t == Integer {
+		t = Fraction
+	}
+
+	out := Number{
+		tpe:  t,
+		base: n.base,
+		atom: n.inv(),
+	}
+
+	if n.tpe == Integer && out.IsInt() {
+		out.tpe = Integer
+	}
+
+	return out.format()
+}
+
+// Fact retourne n!.
+func (n Number) Fact() Number {
+	switch {
+	case n.IsInf():
+		return Inf()
+	case !n.IsInt() || n.IsNeg():
+		return Nan()
+	default:
+		out := One(n.base)
+		for e := Two(); e.Le(n); e = e.Inc() {
+			out.Mul(e)
+		}
+		return out
+	}
+}
+
+// Lsh retourne n1 << n2.
+func (n1 Number) Lsh(n2 Number) Number {
+	if n2.IsNeg() {
+		return n1.Rsh(n2.Abs())
+	}
+
+	if n, ok := n2.toInt64(); ok && n >= 0 {
+		return n1.set(n1.lsh(uint(n)), true)
+	}
+	return Nan()
+}
+
+// Rsh retourne n1 << n2.
+func (n1 Number) Rsh(n2 Number) Number {
+	if n2.IsNeg() {
+		return n1.Lsh(n2.Abs())
+	}
+
+	if n, ok := n2.toInt64(); ok && n >= 0 {
+		return n1.set(n1.rsh(uint(n)), true)
+	}
+	return Nan()
+}
+
+// Len retourne le nombre de chiffre d’un nombre entier (ou -1 s’il n’est pas entier)
+func (n Number) Len() int {
+	return n.len(n.base)
+}
+
+// Bit retourne le chiffre à la position n2 (en partant de 0)
+// d’un nombre entier (ou -1 si n1 ou n2 n’est pas entier).
+func (n1 Number) Bit(n2 Number) int {
+	if n, ok := n2.toInt64(); ok && n >= 0 {
+		return n1.bit(uint64(n), n1.base)
+	}
+
+	return -1
+}
+
+// Pow retourne n1 ^ n2.
+func (n1 Number) Pow(n2 Number) Number {
+	if !n2.IsDefined() {
+		return Nan()
+	}
+
+	p, s := n2.NumDenom()
+	if !p.isInt64() || !s.isInt64() {
+		n2 = n2.set(n2.optimize(pow(n2.base, FloatingPrecision)))
+		p, s = n2.NumDenom()
+		if !p.isInt64() || !s.isInt64() {
+			return Nan()
+		}
+	}
+
+	if p0, ok := p.toInt64(); ok {
+		if s0, ok := s.toInt64(); ok && s0 > 0 {
+			inv := p0 < 0
+			if inv {
+				p0 = -p0
+			}
+			out := Number{
+				tpe:  n1.tpe,
+				base: n1.base,
+				atom: n1.pow(uint64(p0)).sqrtn(uint64(s0), n1.base),
+			}
+			if inv {
+				out.atom = out.atom.inv()
+			}
+			if n1.tpe == Integer && !out.isInt() {
+				out.tpe = Decimal
+			}
+
+			return out.format()
+		}
+	}
+
+	return Nan()
+}
+
+// Sqrtn retourne la racine n2ième de n1.
+func (n1 Number) Sqrtn(n2 Number) Number {
+	if n, ok := n2.toInt64(); ok && n > 0 {
+		out := Number{
+			tpe:  n1.tpe,
+			base: n1.base,
+			atom: n1.sqrtn(uint64(n), n1.base),
+		}
+		if n1.tpe == Integer && !out.isInt() {
+			out.tpe = Decimal
+		}
+
+		return out.format()
+	}
+
+	return Nan()
+}
+
+// Sqrt retourne la racine carrée de n.
+func (n Number) Sqrt() Number {
+	return n.Sqrtn(Int(2))
+}
diff --git a/number/operations.go b/number/operations.go
new file mode 100644
index 0000000..fb7da44
--- /dev/null
+++ b/number/operations.go
@@ -0,0 +1,179 @@
+package number
+
+import (
+	"sort"
+)
+
+type Op1Func func(Number) Number
+type Op2Func func(Number, Number) Number
+type Op1To2Func func(Number) (Number, Number)
+type Op2To2Func func(Number, Number) (Number, Number)
+type ReduceFunc func(...Number) Number
+type MapFunc func(...Number) []Number
+
+func ToBase[N integer](n Number, base N) Number {
+	return n.ToBase(formatBase(base))
+}
+
+func toType[N integer](n Number, t NumberType, base ...N) Number {
+	n = n.ToType(t)
+	if len(base) > 0 {
+		n = ToBase(n, base[0])
+	}
+
+	return n
+}
+
+func ToInteger[N integer](n Number, base ...N) Number {
+	return toType(n, Integer, base...)
+}
+
+func ToDecimal[N integer](n Number, base ...N) Number {
+	return toType(n, Decimal, base...)
+}
+
+func ToFraction[N integer](n Number, base ...N) Number {
+	return toType(n, Fraction, base...)
+}
+
+func ToScientific[N integer](n Number, base ...N) Number {
+	return toType(n, Scientific, base...)
+}
+
+// Fonctions de type f(n) → n
+func Neg(n Number) Number   { return n.Neg() }
+func Abs(n Number) Number   { return n.Abs() }
+func Num(n Number) Number   { return n.Num() }
+func Denom(n Number) Number { return n.Denom() }
+func Inc(n Number) Number   { return n.Inc() }
+func Dec(n Number) Number   { return n.Dec() }
+func Inv(n Number) Number   { return n.Inv() }
+func Fact(n Number) Number  { return n.Fact() }
+func Len(n Number) Number   { return Int(n.Len()) }
+func Sqrt(n Number) Number  { return n.Sqrt() }
+
+// Fonctions de type f(n, n) → n
+func Cmp(n1, n2 Number) Number   { return Int(n1.Cmp(n2)) }
+func Eq(n1, n2 Number) Number    { return ParseBool(n1.Eq(n2)) }
+func Ne(n1, n2 Number) Number    { return ParseBool(n1.Ne(n2)) }
+func Gt(n1, n2 Number) Number    { return ParseBool(n1.Gt(n2)) }
+func Lt(n1, n2 Number) Number    { return ParseBool(n1.Lt(n2)) }
+func Ge(n1, n2 Number) Number    { return ParseBool(n1.Ge(n2)) }
+func Le(n1, n2 Number) Number    { return ParseBool(n1.Le(n2)) }
+func Add(n1, n2 Number) Number   { return n1.Add(n2) }
+func Sub(n1, n2 Number) Number   { return n1.Sub(n2) }
+func Mul(n1, n2 Number) Number   { return n1.Mul(n2) }
+func Div(n1, n2 Number) Number   { return n1.Div(n2) }
+func Quo(n1, n2 Number) Number   { return n1.Quo(n2) }
+func Rem(n1, n2 Number) Number   { return n1.Rem(n2) }
+func Lsh(n1, n2 Number) Number   { return n1.Lsh(n2) }
+func Rsh(n1, n2 Number) Number   { return n1.Rsh(n2) }
+func Bit(n1, n2 Number) Number   { return Int(n1.Bit(n2)) }
+func Pow(n1, n2 Number) Number   { return n1.Pow(n2) }
+func Sqrtn(n1, n2 Number) Number { return n1.Sqrtn(n2) }
+
+// Fonctions de type f(n) → (n, n)
+func NumDenom(n Number) (Number, Number) { return n.NumDenom() }
+
+// Fonctions de type f(n, n) → (n, n)
+func QuoRem(n1, n2 Number) (Number, Number) { return n1.QuoRem(n2) }
+
+// Autre
+func Map(callback Op1Func) MapFunc {
+	return func(numbers ...Number) []Number {
+		out := make([]Number, len(numbers))
+		for i, n := range numbers {
+			out[i] = callback(n)
+		}
+
+		return out
+	}
+}
+
+func Reduce(callback Op2Func) ReduceFunc {
+	return func(numbers ...Number) Number {
+		var acc Number
+		for i, n := range numbers {
+			if i == 0 {
+				acc = n
+			} else {
+				acc = callback(acc, n)
+			}
+		}
+
+		return acc
+	}
+}
+
+func Max(numbers ...Number) (n Number) {
+	return Reduce(func(n1, n2 Number) Number {
+		if n2.Gt(n1) {
+			return n2
+		}
+		return n1
+	})(numbers...)
+}
+
+func Min(numbers ...Number) (n Number) {
+	return Reduce(func(n1, n2 Number) Number {
+		if n2.Lt(n1) {
+			return n2
+		}
+		return n1
+	})(numbers...)
+}
+
+func Sum(numbers ...Number) (n Number) {
+	return Reduce(Add)(numbers...)
+}
+
+func Mean(numbers ...Number) (n Number) {
+	l := len(numbers)
+	if l == 0 {
+		return Nan()
+	}
+
+	return Sum(numbers...).Div(Int(l))
+}
+
+func Round(n Number, precision uint64, base ...uint) Number {
+	if !n.IsDefined() || n.Type() == Integer {
+		return n
+	}
+
+	p := Number{
+		base: n.Base(),
+		tpe:  n.Type(),
+		atom: pow(formatBase(base...), precision),
+	}
+	p.format()
+	num, denom := n.Num().Mul(p), n.Denom()
+
+	return num.Quo(denom).Div(p)
+}
+
+func Reverse(numbers ...Number) []Number {
+	l := len(numbers)
+	for i := 0; i < l>>1; i++ {
+		j := l - 1 - i
+		numbers[i], numbers[j] = numbers[j], numbers[i]
+	}
+
+	return numbers
+}
+
+func Sort(numbers ...Number) []Number {
+	sort.Slice(numbers, func(i, j int) bool {
+		return numbers[i].Lt(numbers[j])
+	})
+
+	return numbers
+}
+
+func SortDesc(numbers ...Number) []Number {
+	sort.Slice(numbers, func(i, j int) bool {
+		return numbers[i].Gt(numbers[j])
+	})
+
+	return numbers
+}
diff --git a/number/util.go b/number/util.go
new file mode 100644
index 0000000..219f2b2
--- /dev/null
+++ b/number/util.go
@@ -0,0 +1,36 @@
+package number
+
+type integer interface {
+	~int | ~int8 | ~int16 | ~int32 | ~int64 | ~uint | ~uint8 | ~uint16 | ~uint32 | ~uint64
+}
+
+type float interface {
+	~float32 | ~float64
+}
+
+func signOf[N integer | float](n N) int {
+	switch {
+	case n < 0:
+		return -1
+	case n > 0:
+		return 1
+	default:
+		return 0
+	}
+}
+
+func compare[N integer | float](n1, n2 N) int {
+	return signOf(n1 - n2)
+}
+
+func isBaseValid[N integer | float](base N) bool {
+	return base >= 0 && base <= 36
+}
+
+func formatBase[N integer | float](base ...N) uint {
+	if len(base) > 0 && isBaseValid(base[0]) {
+		return uint(base[0])
+	}
+
+	return 10
+}