Add 72/4 and 36/21
1st number: 18 0/4, 2nd number: 1 15/21
72/4 + 36/21 is 138/7.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 4 and 21 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 4 × 21 = 84,
72/4 = 72 × 21/4 × 21 = 1512/84 - Likewise, for the 2nd fraction, since 21 × 4 = 84,
36/21 = 36 × 4/21 × 4 = 144/84 - Add the two like fractions:
1512/84 + 144/84 = 1512 + 144/84 = 1656/84 - 1656/84 simplified gives 138/7
- So, 72/4 + 36/21 = 138/7
In mixed form: 195/7
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 72/4+72/21 72/8+36/21 72/4+36/42 72/12+36/21 72/4+36/63 72/20+36/21 72/28+36/21