Add 70/90 and 21/20
1st number: 70/90, 2nd number: 1 1/20
70/90 + 21/20 is 329/180.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 90 and 20 is 180
Next, find the equivalent fraction of both fractional numbers with denominator 180 - For the 1st fraction, since 90 × 2 = 180,
70/90 = 70 × 2/90 × 2 = 140/180 - Likewise, for the 2nd fraction, since 20 × 9 = 180,
21/20 = 21 × 9/20 × 9 = 189/180 - Add the two like fractions:
140/180 + 189/180 = 140 + 189/180 = 329/180 - So, 70/90 + 21/20 = 329/180
In mixed form: 1149/180
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 70/90+42/20 70/90+21/40 70/90+63/20 70/90+21/60