Add 21/30 and 72/56
1st number: 21/30, 2nd number: 1 16/56
21/30 + 72/56 is 139/70.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 30 and 56 is 840
Next, find the equivalent fraction of both fractional numbers with denominator 840 - For the 1st fraction, since 30 × 28 = 840,
21/30 = 21 × 28/30 × 28 = 588/840 - Likewise, for the 2nd fraction, since 56 × 15 = 840,
72/56 = 72 × 15/56 × 15 = 1080/840 - Add the two like fractions:
588/840 + 1080/840 = 588 + 1080/840 = 1668/840 - 1668/840 simplified gives 139/70
- So, 21/30 + 72/56 = 139/70
In mixed form: 169/70
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/30+72/56 21/60+72/56 63/30+72/56 21/90+72/56