reduce very large fractions close to a whole number to the whole number

fractional/src/fractional.rs

@@ -86,8 +86,18 @@ impl Fractional {
     #[inline]
     pub fn reduce(self) -> Self {
         let Fractional(n, d) = self;
+        let (_n, _d) = if n > d { (n, d) } else { (d, n) };
+
+        // if the difference from _n % _d to _n is very big we are close to
+        // a whole number and can ignore the fractional part... this reduces
+        // the precision but ensures smaller numbers for numerator and
+        // denominator.
+        if _d > 1 && (_n % _d) * 10000000 < _n {
+            Self(_n / _d, 1)
+        } else {
             Self(n / hcf(n, d), d / hcf(n, d))
         }
+    }
 
     #[inline]
     pub fn numerator(self) -> i64 {