Answer: John grew 4 and 3/4 inches in one year.
Explanation:
Start by subtracting 64.375 (64 and 3/8) by 59.625 (59 and 5/8).
Type your numbers into a calculator (both ways can be put into your calculator, but decimals are easier for you to type)
Get your final answer of 4.75.
Hope this helps!