Add 21/28 and 63/80
21/28 + 63/80 is 123/80.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 28 and 80 is 560
Next, find the equivalent fraction of both fractional numbers with denominator 560 - For the 1st fraction, since 28 × 20 = 560,
21/28 = 21 × 20/28 × 20 = 420/560 - Likewise, for the 2nd fraction, since 80 × 7 = 560,
63/80 = 63 × 7/80 × 7 = 441/560 - Add the two like fractions:
420/560 + 441/560 = 420 + 441/560 = 861/560 - 861/560 simplified gives 123/80
- So, 21/28 + 63/80 = 123/80
In mixed form: 143/80
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/28+63/80 21/56+63/80 63/28+63/80 21/84+63/80