Add 70/60 and 81/21
1st number: 1 10/60, 2nd number: 3 18/21
70/60 + 81/21 is 211/42.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 60 and 21 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 60 × 7 = 420,
70/60 = 70 × 7/60 × 7 = 490/420 - Likewise, for the 2nd fraction, since 21 × 20 = 420,
81/21 = 81 × 20/21 × 20 = 1620/420 - Add the two like fractions:
490/420 + 1620/420 = 490 + 1620/420 = 2110/420 - 2110/420 simplified gives 211/42
- So, 70/60 + 81/21 = 211/42
In mixed form: 51/42
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 70/60+81/42 70/60+81/63