Add 21/18 and 42/30
1st number: 1 3/18, 2nd number: 1 12/30
21/18 + 42/30 is 77/30.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 18 and 30 is 90
Next, find the equivalent fraction of both fractional numbers with denominator 90 - For the 1st fraction, since 18 × 5 = 90,
21/18 = 21 × 5/18 × 5 = 105/90 - Likewise, for the 2nd fraction, since 30 × 3 = 90,
42/30 = 42 × 3/30 × 3 = 126/90 - Add the two like fractions:
105/90 + 126/90 = 105 + 126/90 = 231/90 - 231/90 simplified gives 77/30
- So, 21/18 + 42/30 = 77/30
In mixed form: 217/30
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/18+42/30 21/18+84/30 21/36+42/30 21/18+42/60 63/18+42/30 21/54+42/30 21/18+42/90 21/90+42/30