To write a fraction in simplest form, you have to divide the numerator and the denominator by their greatest common factor.
Factors of 10: 1, 2, 5, 10
Factors of 64: 1, 2, 4, 8, 16, 32, 64
Common Factors: 1, 2
Greatest Common Factor: 2
[tex] \frac{10}{64} = \frac{10/2}{64/2} = \frac{5}{32} [/tex]