Add 28/21 and 4/20
1st number: 1 7/21, 2nd number: 4/20
28/21 + 4/20 is 23/15.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 20 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 21 × 20 = 420,
28/21 = 28 × 20/21 × 20 = 560/420 - Likewise, for the 2nd fraction, since 20 × 21 = 420,
4/20 = 4 × 21/20 × 21 = 84/420 - Add the two like fractions:
560/420 + 84/420 = 560 + 84/420 = 644/420 - 644/420 simplified gives 23/15
- So, 28/21 + 4/20 = 23/15
In mixed form: 18/15
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 56/21+4/20 28/21+8/20 28/42+4/20 28/21+4/40 84/21+4/20 28/21+12/20 28/63+4/20 28/21+4/60 28/21+28/20