Add 21/4 and 42/63
1st number: 5 1/4, 2nd number: 42/63
21/4 + 42/63 is 71/12.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 4 and 63 is 252
Next, find the equivalent fraction of both fractional numbers with denominator 252 - For the 1st fraction, since 4 × 63 = 252,
21/4 = 21 × 63/4 × 63 = 1323/252 - Likewise, for the 2nd fraction, since 63 × 4 = 252,
42/63 = 42 × 4/63 × 4 = 168/252 - Add the two like fractions:
1323/252 + 168/252 = 1323 + 168/252 = 1491/252 - 1491/252 simplified gives 71/12
- So, 21/4 + 42/63 = 71/12
In mixed form: 511/12
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/4+42/63 21/4+84/63 21/8+42/63 63/4+42/63 21/12+42/63 21/20+42/63 21/28+42/63