To convert decimal form into fraction form, you first take the decimal point away and divide the number by 10; the more digits the number has, the more zeros you need to add behind ten. 0.4 becomes 4/10 and 0.25 becomes 25/100(because it has two digits, there are two zeroes in the denominator*; it is 100). *the denominator is the number at the bottom of a fraction, and the numerator is at the top. Numerator/Denominator.