Equivalent fractions and multiplying by a whole number

Multiplying a fraction by a whole number is repeated addition. 3 × 2/5 means 2/5 + 2/5 + 2/5. Three groups of 2 fifths make 6 fifths, so 3 × 2/5 = 6/5 = 1 1/5. The pieces are still fifths, so only the numerator is multiplied: 3 × 2 = 6, and the denominator stays 5. We never multiply the denominator, because the size of the pieces does not change. If the product is bigger than the denominator we can write it as a mixed number: 6 × 3/4 = 18/4 = 4 2/4. In a story, find how many equal groups there are and how much is in each group. A jug pours 3/4 of a litre into each of 4 glasses: 4 × 3/4 = 12/4 = 3 litres.