You can write 63.5 in simplest form, but have to covert to fractions. 63.5 is equal to 63_5/10. The "5/10" can be simplified into 1/2. Therefore, the simplified version of 63_5/10 is 63_1/2.
(The "_" is just for space. Please don't put it in your real answer. It just means it's not the same number.)