Add 40/84 and 21/70
40/84 + 21/70 is 163/210.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 84 and 70 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 84 × 5 = 420,
40/84 = 40 × 5/84 × 5 = 200/420 - Likewise, for the 2nd fraction, since 70 × 6 = 420,
21/70 = 21 × 6/70 × 6 = 126/420 - Add the two like fractions:
200/420 + 126/420 = 200 + 126/420 = 326/420 - 326/420 simplified gives 163/210
- So, 40/84 + 21/70 = 163/210
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 80/84+21/70 40/84+42/70 40/84+63/70