In the decimal 3.8, the whole number is 3, so we can automatically see that 3 will be the whole number of a mixef number. 8 in 3.8 is in the tenths place, so 8 will be the numerator and the denominator will be 10. Your fraction is 3 8/10, but we know must simplify. 8 divided by 2 is 4, and 10 divided by 2 is 5. Your final fraction is 3 4/5