diff --git a/number/const.go b/number/const.go
index 3a1ee97..808c1c9 100644
--- a/number/const.go
+++ b/number/const.go
@@ -11,16 +11,16 @@ var (
 )
 
 const (
-	rSign   = `(\+|-)`
+	rSign   = `\+|-`
 	rBSign  = `(0|1)`
 	rNb2    = `(0|1)`
 	rNb8    = `[0-7]`
 	rNb10   = `\d`
 	rNb16   = `[0-9a-fA-F]`
 	rNbN    = `[0-9a-zA-Z]`
-	rBase2  = `(B|b)`
-	rBase8  = `(O|o)`
-	rBase16 = `(X|x)`
+	rBase2  = `B|b`
+	rBase8  = `O|o`
+	rBase16 = `X|x`
 	rExp10  = `E|e`
 	rExpN   = `×\d+\^`
 )
@@ -28,23 +28,23 @@ const (
 var (
 	rInt2  = fmt.Sprintf(`(%s)%s+`, rBase2, rNb2)
 	rInt8  = fmt.Sprintf(`(%s)%s+`, rBase8, rNb8)
-	rInt10 = fmt.Sprintf(`(%s)%s+`, rSign, rNb10)
-	rInt16 = fmt.Sprintf(`(%s)%s+`, rBase8, rNb8)
-	rIntN  = fmt.Sprintf(`\(%s+\)%s?%s+`, rNb10, rSign, rNbN)
+	rInt10 = fmt.Sprintf(`(%s)?%s+`, rSign, rNb10)
+	rInt16 = fmt.Sprintf(`(%s)%s+`, rBase16, rNb16)
+	rIntN  = fmt.Sprintf(`\(%s+\)(%s)?%s+`, rNb10, rSign, rNbN)
 	rIntB  = fmt.Sprintf(`%s(%s|%s|%s)`, rBSign, rInt2, rInt8, rInt16)
 	rInt   = fmt.Sprintf(`(%s|%s|%s)`, rInt10, rIntN, rIntB)
 
 	rDec2       = fmt.Sprintf(`(%s)(%s+\.%s*|\.%s+)`, rBase2, rNb2, rNb2, rNb2)
 	rDec8       = fmt.Sprintf(`(%s)(%s+\.%s*|\.%s+)`, rBase8, rNb8, rNb8, rNb8)
-	rDec10      = fmt.Sprintf(`%s?(%s+\.%s*|\.%s+)`, rSign, rNb10, rNb10, rNb10)
+	rDec10      = fmt.Sprintf(`(%s)?(%s+\.%s*|\.%s+)`, rSign, rNb10, rNb10, rNb10)
 	rDec16      = fmt.Sprintf(`(%s)(%s+\.%s*|\.%s+)`, rBase16, rNb16, rNb16, rNb16)
-	rDecN       = fmt.Sprintf(`\(%s+\)%s?(%s+\.%s*|\.%s+)`, rNb10, rSign, rNbN, rNbN, rNbN)
+	rDecN       = fmt.Sprintf(`\(%s+\)(%s)?(%s+\.%s*|\.%s+)`, rNb10, rSign, rNbN, rNbN, rNbN)
 	rDecB       = fmt.Sprintf(`%s(%s|%s|%s)`, rBSign, rDec2, rDec8, rDec16)
 	rDec        = fmt.Sprintf(`(%s|%s|%s)`, rDec10, rDecN, rDecB)
-	rExponent10 = fmt.Sprintf(`(%s|%s)(%s)%s?%s+`, rInt10, rDec10, rExp10, rSign, rNb10)
-	rExponentN  = fmt.Sprintf(`(%s|%s)%s%s?%s+`, rInt, rDec, rExpN, rSign, rNb10)
-	rAll10      = fmt.Sprintf(`(%s|%s)((%s)%s?%s+)?`, rInt10, rDec10, regExp10, rSign, rNb10)
-	rAllN       = fmt.Sprintf(`(%s|%s)(%s%s?%s+)?`, rInt, rDec, rExpN, rSign, rNb10)
+	rExponent10 = fmt.Sprintf(`(%s|%s)(%s)(%s)?%s+`, rInt10, rDec10, rExp10, rSign, rNb10)
+	rExponentN  = fmt.Sprintf(`(%s|%s)%s(%s)?%s+`, rInt, rDec, rExpN, rSign, rNb10)
+	rAll10      = fmt.Sprintf(`(%s|%s)((%s)(%s)?%s+)?`, rInt10, rDec10, regExp10, rSign, rNb10)
+	rAllN       = fmt.Sprintf(`(%s|%s)(%s(%s)?%s+)?`, rInt, rDec, rExpN, rSign, rNb10)
 	rAll        = fmt.Sprintf(`(%s|%s)`, rAll10, rAllN)
 )
 
@@ -56,7 +56,7 @@ var (
 	regDec = regexp.MustCompile(fmt.Sprintf(`^%s$`, rDec))
 
 	regExp10 = regexp.MustCompile(fmt.Sprintf(`^%s$`, rExponent10))
-	regExpN  = regexp.MustCompile(fmt.Sprintf(`^%s$`, rExpN))
+	regExpN  = regexp.MustCompile(fmt.Sprintf(`^%s$`, rExponentN))
 
 	regFrac = regexp.MustCompile(fmt.Sprintf(`^%s/%s$`, rAll, rAll))
 )
diff --git a/number/convert.go b/number/convert.go
index 39bcfa7..bdf6cec 100644
--- a/number/convert.go
+++ b/number/convert.go
@@ -233,7 +233,7 @@ func Parse(str string) (out option.Option[Number]) {
 		}
 	case regExpN.MatchString(str):
 		i, j := strings.Index(str, "×"), strings.Index(str, "^")
-		if expBase, err := strconv.ParseUint(str[i+1:j], 10, 64); err == nil && isBaseValid(expBase) {
+		if expBase, err := strconv.ParseUint(str[i+2:j], 10, 64); err == nil && isBaseValid(expBase) {
 			if exponent, err := strconv.Atoi(str[j+1:]); err == nil {
 				if n, ok := Parse(str[:i]).Get(); ok {
 					out = option.Some(n.Mul(pow(expBase, exponent)).ToType(Scientific))
@@ -242,7 +242,7 @@ func Parse(str string) (out option.Option[Number]) {
 		}
 	case regFrac.MatchString(str):
 		i := strings.Index(str, "/")
-		num, denom := Parse(str[:i]), Parse(str[i:])
+		num, denom := Parse(str[:i]), Parse(str[i+1:])
 		if n, ok := num.Get(); ok {
 			if d, ok := denom.Get(); ok {
 				out = option.Some(n.Div(d).ToType(Fraction))
diff --git a/number/number.go b/number/number.go
index 320b2bc..fc36be5 100644
--- a/number/number.go
+++ b/number/number.go
@@ -31,10 +31,10 @@ func (n *Number) get() (r *big.Rat, ok bool) {
 }
 
 func (n *Number) rat() (r *big.Rat, ok bool) {
-	if r, ok := n.get(); ok {
+	if r, ok = n.get(); ok {
 		r = new(big.Rat).Set(r)
 		if n.Sign() < 0 {
-			r = r.Neg(r)
+			r.Neg(r)
 		}
 	}