Math: As unit conversion algorithm fails with high precision, make significant digits matter.

plugins/Math/plugin.py

@@ -308,9 +308,19 @@ class Math(callbacks.Plugin):
         Converts from <unit> to <other unit>. If number isn't given, it
         defaults to 1. For unit information, see 'units' command.
         """
+        try:
+            digits = len(str(number).split('.')[1])
+        except IndexError:
+            digits = 0
         try:
             newNum = convertcore.convert(number, unit1, unit2)
             newNum = self._floatToString(newNum)
+            if isinstance(newNum, float):
+                # Let's add one signifiant digit. Physicists would not like
+                # that, but common people usually do not give extra zeros...
+                # (for example, with '32 C to F', an extra digit would be
+                # expected).
+                newNum = round(newNum, digits+1)
             irc.reply(str(newNum))
         except convertcore.UnitDataError, ude:
             irc.error(str(ude))