Think of % as hundredths 1% is one hundredth, 2% is two hundredths. So 65% is 65 hundredths. One hundredth shown as a decimal is 0.01, two hundredths would be 0.02, and it's the same all the way up, so 65 hundredths ( 65%) is shown as 0.65 as a decimal

All you do is add a zero and a decimal like 0.65 or if you have 5 percent you add a zero, decimal, another zero than 5 like 0.05