Add 72/21 and 90/56
1st number: 3 9/21, 2nd number: 1 34/56
72/21 + 90/56 is 141/28.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 56 is 168
Next, find the equivalent fraction of both fractional numbers with denominator 168 - For the 1st fraction, since 21 × 8 = 168,
72/21 = 72 × 8/21 × 8 = 576/168 - Likewise, for the 2nd fraction, since 56 × 3 = 168,
90/56 = 90 × 3/56 × 3 = 270/168 - Add the two like fractions:
576/168 + 270/168 = 576 + 270/168 = 846/168 - 846/168 simplified gives 141/28
- So, 72/21 + 90/56 = 141/28
In mixed form: 51/28
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 72/42+90/56 72/63+90/56