Add 21/70 and 12/84
21/70 + 12/84 is 31/70.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 70 and 84 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 70 × 6 = 420,
21/70 = 21 × 6/70 × 6 = 126/420 - Likewise, for the 2nd fraction, since 84 × 5 = 420,
12/84 = 12 × 5/84 × 5 = 60/420 - Add the two like fractions:
126/420 + 60/420 = 126 + 60/420 = 186/420 - 186/420 simplified gives 31/70
- So, 21/70 + 12/84 = 31/70
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/70+12/84 21/70+24/84 63/70+12/84 21/70+36/84 21/70+60/84