Add 20/28 and 25/21
1st number: 20/28, 2nd number: 1 4/21
20/28 + 25/21 is 40/21.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 28 and 21 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 28 × 3 = 84,
20/28 = 20 × 3/28 × 3 = 60/84 - Likewise, for the 2nd fraction, since 21 × 4 = 84,
25/21 = 25 × 4/21 × 4 = 100/84 - Add the two like fractions:
60/84 + 100/84 = 60 + 100/84 = 160/84 - 160/84 simplified gives 40/21
- So, 20/28 + 25/21 = 40/21
In mixed form: 119/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 40/28+25/21 20/28+50/21 20/56+25/21 20/28+25/42 60/28+25/21 20/28+75/21 20/84+25/21 20/28+25/63