Fractions to Decimals and Percentages Worksheets To convert a fraction into percentages, you can take up two approaches. The first one is to convert a fraction into a decimal and multiply it by 100 or simply take the fraction and multiply it by 100. Method 1 - As we have already converted the fraction 2/5 into a decimal. We can now multiply it by 100 to find the percentage. 0.4 × 100 = 40%.