Add 21/7 and 28/80
1st number: 3 0/7, 2nd number: 28/80
21/7 + 28/80 is 67/20.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 7 and 80 is 560
Next, find the equivalent fraction of both fractional numbers with denominator 560 - For the 1st fraction, since 7 × 80 = 560,
21/7 = 21 × 80/7 × 80 = 1680/560 - Likewise, for the 2nd fraction, since 80 × 7 = 560,
28/80 = 28 × 7/80 × 7 = 196/560 - Add the two like fractions:
1680/560 + 196/560 = 1680 + 196/560 = 1876/560 - 1876/560 simplified gives 67/20
- So, 21/7 + 28/80 = 67/20
In mixed form: 37/20
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/7+28/80 21/7+56/80 21/14+28/80 63/7+28/80 21/7+84/80 21/35+28/80 21/49+28/80