Answer :

[tex]64|\fbox2\\32|\fbox2\\16|2\\.\ 8|2\\.\ 4|2\\.\ 2|2\\.\ 1|\\-----------\\100|\fbox2\\.\ 50|\fbox2\\.\ 25|5\\.\ \ 5|5\\.\ \ 1|\\\\GCF(64;100)=2\times2=4\\\\\boxed{\frac{64}{100}=\frac{64:4}{100:4}=\frac{16}{25}}[/tex]
first i would didvide each by 2 = 32/50 then by 2 again =16/25
and then that i the simplest fraction
also you could just divide both numbers by 4