Add 21/30 and 12/7
1st number: 21/30, 2nd number: 1 5/7
21/30 + 12/7 is 169/70.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 30 and 7 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 30 × 7 = 210,
21/30 = 21 × 7/30 × 7 = 147/210 - Likewise, for the 2nd fraction, since 7 × 30 = 210,
12/7 = 12 × 30/7 × 30 = 360/210 - Add the two like fractions:
147/210 + 360/210 = 147 + 360/210 = 507/210 - 507/210 simplified gives 169/70
- So, 21/30 + 12/7 = 169/70
In mixed form: 229/70
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/30+12/7 21/30+24/7 21/60+12/7 21/30+12/14 63/30+12/7 21/30+36/7 21/90+12/7 21/30+12/21 21/30+60/7 21/30+12/35 21/30+84/7 21/30+12/49