Add 21/70 and 42/30
1st number: 21/70, 2nd number: 1 12/30
21/70 + 42/30 is 17/10.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 70 and 30 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 70 × 3 = 210,
21/70 = 21 × 3/70 × 3 = 63/210 - Likewise, for the 2nd fraction, since 30 × 7 = 210,
42/30 = 42 × 7/30 × 7 = 294/210 - Add the two like fractions:
63/210 + 294/210 = 63 + 294/210 = 357/210 - 357/210 simplified gives 17/10
- So, 21/70 + 42/30 = 17/10
In mixed form: 17/10
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/70+42/30 21/70+84/30 21/70+42/60 63/70+42/30 21/70+42/90