Add 21/28 and 28/70
21/28 + 28/70 is 23/20.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 28 and 70 is 140
Next, find the equivalent fraction of both fractional numbers with denominator 140 - For the 1st fraction, since 28 × 5 = 140,
21/28 = 21 × 5/28 × 5 = 105/140 - Likewise, for the 2nd fraction, since 70 × 2 = 140,
28/70 = 28 × 2/70 × 2 = 56/140 - Add the two like fractions:
105/140 + 56/140 = 105 + 56/140 = 161/140 - 161/140 simplified gives 23/20
- So, 21/28 + 28/70 = 23/20
In mixed form: 13/20
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/28+28/70 21/28+56/70 21/56+28/70 63/28+28/70 21/28+84/70 21/84+28/70