Add 21/15 and 84/72
1st number: 1 6/15, 2nd number: 1 12/72
21/15 + 84/72 is 77/30.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 15 and 72 is 360
Next, find the equivalent fraction of both fractional numbers with denominator 360 - For the 1st fraction, since 15 × 24 = 360,
21/15 = 21 × 24/15 × 24 = 504/360 - Likewise, for the 2nd fraction, since 72 × 5 = 360,
84/72 = 84 × 5/72 × 5 = 420/360 - Add the two like fractions:
504/360 + 420/360 = 504 + 420/360 = 924/360 - 924/360 simplified gives 77/30
- So, 21/15 + 84/72 = 77/30
In mixed form: 217/30
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/15+84/72 21/30+84/72 63/15+84/72 21/45+84/72 21/75+84/72