Add 21/4 and 72/20
1st number: 5 1/4, 2nd number: 3 12/20
21/4 + 72/20 is 177/20.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 4 and 20 is 20
Next, find the equivalent fraction of both fractional numbers with denominator 20 - For the 1st fraction, since 4 × 5 = 20,
21/4 = 21 × 5/4 × 5 = 105/20 - Likewise, for the 2nd fraction, since 20 × 1 = 20,
72/20 = 72 × 1/20 × 1 = 72/20 - Add the two like fractions:
105/20 + 72/20 = 105 + 72/20 = 177/20 - So, 21/4 + 72/20 = 177/20
In mixed form: 817/20
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/4+72/20 21/8+72/20 21/4+72/40 63/4+72/20 21/12+72/20 21/4+72/60 21/20+72/20 21/28+72/20