Add 21/4 and 40/21
1st number: 5 1/4, 2nd number: 1 19/21
21/4 + 40/21 is 601/84.
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,
21/4 = 21 × 21/4 × 21 = 441/84 - Likewise, for the 2nd fraction, since 21 × 4 = 84,
40/21 = 40 × 4/21 × 4 = 160/84 - Add the two like fractions:
441/84 + 160/84 = 441 + 160/84 = 601/84 - So, 21/4 + 40/21 = 601/84
In mixed form: 713/84
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/4+40/21 21/4+80/21 21/8+40/21 21/4+40/42 63/4+40/21 21/12+40/21 21/4+40/63 21/20+40/21 21/28+40/21