Add 21/42 and 45/56
21/42 + 45/56 is 73/56.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 56 is 168
Next, find the equivalent fraction of both fractional numbers with denominator 168 - For the 1st fraction, since 42 × 4 = 168,
21/42 = 21 × 4/42 × 4 = 84/168 - Likewise, for the 2nd fraction, since 56 × 3 = 168,
45/56 = 45 × 3/56 × 3 = 135/168 - Add the two like fractions:
84/168 + 135/168 = 84 + 135/168 = 219/168 - 219/168 simplified gives 73/56
- So, 21/42 + 45/56 = 73/56
In mixed form: 117/56
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 21/42+90/56 21/84+45/56 63/42+45/56