The answer is simple. To convert a fraction into a decimal take the numerator(the top number) and divide it by the denominator(the bottom number) so the fraction shown above is 4/10. There are two ways. Number 1: u know that 1/10 equals 0.1 so 4/10 equals 0.4 because the 4 needs to be in the tenths place. Number 2: take 4 (numerator) divide it by 10 (denominator) so 4 divided by 10 equals 0.4 so your answer is C=0.40. (PS: 0.4=0.40)