Add 21/18 and 40/42
1st number: 1 3/18, 2nd number: 40/42
21/18 + 40/42 is 89/42.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 18 and 42 is 126
Next, find the equivalent fraction of both fractional numbers with denominator 126 - For the 1st fraction, since 18 × 7 = 126,
21/18 = 21 × 7/18 × 7 = 147/126 - Likewise, for the 2nd fraction, since 42 × 3 = 126,
40/42 = 40 × 3/42 × 3 = 120/126 - Add the two like fractions:
147/126 + 120/126 = 147 + 120/126 = 267/126 - 267/126 simplified gives 89/42
- So, 21/18 + 40/42 = 89/42
In mixed form: 25/42
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/18+40/42 21/18+80/42 21/36+40/42 21/18+40/84 63/18+40/42 21/54+40/42 21/90+40/42