Add 21/15 and 40/42
1st number: 1 6/15, 2nd number: 40/42
21/15 + 40/42 is 247/105.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 15 and 42 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 15 × 14 = 210,
21/15 = 21 × 14/15 × 14 = 294/210 - Likewise, for the 2nd fraction, since 42 × 5 = 210,
40/42 = 40 × 5/42 × 5 = 200/210 - Add the two like fractions:
294/210 + 200/210 = 294 + 200/210 = 494/210 - 494/210 simplified gives 247/105
- So, 21/15 + 40/42 = 247/105
In mixed form: 237/105
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/15+40/42 21/15+80/42 21/30+40/42 21/15+40/84 63/15+40/42 21/45+40/42 21/75+40/42