diff --git a/src/cgmath/projection.rs b/src/cgmath/projection.rs
index 74dea98..cd8f2d6 100644
--- a/src/cgmath/projection.rs
+++ b/src/cgmath/projection.rs
@@ -112,6 +112,7 @@ impl<S: Float, A: Angle<S>> ToMat4<S> for PerspectiveFov<S, A> {
         assert!(self.far    < self.near, "The far plane cannot be closer than the near plane, found: far: %?, near: %?", self.far, self.near);
 
         let f = cot(self.fovy.div_s(cast(2)));
+        let two: S = cast(2);
 
         let c0r0 = f / self.aspect;
         let c0r1 = zero();
@@ -130,7 +131,7 @@ impl<S: Float, A: Angle<S>> ToMat4<S> for PerspectiveFov<S, A> {
 
         let c3r0 = zero();
         let c3r1 = zero();
-        let c3r2 = (cast::<int, S>(2) * self.far * self.near) / (self.near - self.far);
+        let c3r2 = (two * self.far * self.near) / (self.near - self.far);
         let c3r3 = zero();
 
         Mat4::new(c0r0, c0r1, c0r2, c0r3,
@@ -161,13 +162,15 @@ impl<S: Float> ToMat4<S> for Perspective<S> {
         assert!(self.bottom > self.top,   "`bottom` cannot be greater than `top`, found: bottom: %? top: %?", self.bottom, self.top);
         assert!(self.near   > self.far,   "`near` cannot be greater than `far`, found: near: %? far: %?", self.near, self.far);
 
-        let c0r0 = (cast::<int, S>(2) * self.near) / (self.right - self.left);
+        let two: S = cast(2);
+
+        let c0r0 = (two * self.near) / (self.right - self.left);
         let c0r1 = zero();
         let c0r2 = zero();
         let c0r3 = zero();
 
         let c1r0 = zero();
-        let c1r1 = (cast::<int, S>(2) * self.near) / (self.top - self.bottom);
+        let c1r1 = (two * self.near) / (self.top - self.bottom);
         let c1r2 = zero();
         let c1r3 = zero();
 
@@ -178,7 +181,7 @@ impl<S: Float> ToMat4<S> for Perspective<S> {
 
         let c3r0 = zero();
         let c3r1 = zero();
-        let c3r2 = -(cast::<int, S>(2) * self.far * self.near) / (self.far - self.near);
+        let c3r2 = -(two * self.far * self.near) / (self.far - self.near);
         let c3r3 = zero();
 
         Mat4::new(c0r0, c0r1, c0r2, c0r3,
@@ -215,19 +218,21 @@ impl<S: Float> ToMat4<S> for Ortho<S> {
         assert!(self.bottom > self.top,   "`bottom` cannot be greater than `top`, found: bottom: %? top: %?", self.bottom, self.top);
         assert!(self.near   > self.far,   "`near` cannot be greater than `far`, found: near: %? far: %?", self.near, self.far);
 
-        let c0r0 = cast::<int, S>(2) / (self.right - self.left);
+        let two: S = cast(2);
+
+        let c0r0 = two / (self.right - self.left);
         let c0r1 = zero();
         let c0r2 = zero();
         let c0r3 = zero();
 
         let c1r0 = zero();
-        let c1r1 = cast::<int, S>(2) / (self.top - self.bottom);
+        let c1r1 = two / (self.top - self.bottom);
         let c1r2 = zero();
         let c1r3 = zero();
 
         let c2r0 = zero();
         let c2r1 = zero();
-        let c2r2 = -cast::<int, S>(2) / (self.far - self.near);
+        let c2r2 = -two / (self.far - self.near);
         let c2r3 = -one::<S>();
 
         let c3r0 = -(self.right + self.left) / (self.right - self.left);
diff --git a/src/cgmath/rotation.rs b/src/cgmath/rotation.rs
index 2922dec..eae3973 100644
--- a/src/cgmath/rotation.rs
+++ b/src/cgmath/rotation.rs
@@ -311,9 +311,9 @@ impl<S: Float, A: Angle<S>> ToRot3<S> for Euler<A> {
 impl<S: Float, A: Angle<S>> ToQuat<S> for Euler<A> {
     fn to_quat(&self) -> Quat<S> {
         // http://en.wikipedia.org/wiki/Conversion_between_quaternions_and_Euler_angles#Conversion
-        let (sx2, cx2) = sin_cos(self.x.div_s(cast(2)));
-        let (sy2, cy2) = sin_cos(self.y.div_s(cast(2)));
-        let (sz2, cz2) = sin_cos(self.z.div_s(cast(2)));
+        let (sx2, cx2) = sin_cos(self.x.mul_s(cast(0.5)));
+        let (sy2, cy2) = sin_cos(self.y.mul_s(cast(0.5)));
+        let (sz2, cz2) = sin_cos(self.z.mul_s(cast(0.5)));
 
         Quat::new(cz2 * cx2 * cy2 + sz2 * sx2 * sy2,
                   sz2 * cx2 * cy2 - cz2 * sx2 * sy2,
@@ -415,7 +415,7 @@ impl<S: Float, A: Angle<S>> ToRot3<S> for AxisAngle<S, A> {
 
 impl<S: Float, A: Angle<S>> ToQuat<S> for AxisAngle<S, A> {
     fn to_quat(&self) -> Quat<S> {
-        let half = self.a.div_s(cast(2));
+        let half = self.a.mul_s(cast(0.5));
         Quat::from_sv(
             cos(half.clone()),
             self.v.mul_s(sin(half.clone()))