Add 21/4 and 20/42
1st number: 5 1/4, 2nd number: 20/42
21/4 + 20/42 is 481/84.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 4 and 42 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 42 × 2 = 84,
20/42 = 20 × 2/42 × 2 = 40/84 - Add the two like fractions:
441/84 + 40/84 = 441 + 40/84 = 481/84 - So, 21/4 + 20/42 = 481/84
In mixed form: 561/84
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/4+20/42 21/4+40/42 21/8+20/42 21/4+20/84 63/4+20/42 21/4+60/42 21/12+20/42 21/20+20/42 21/28+20/42