Add 21/70 and 18/30
21/70 + 18/30 is 9/10.
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,
18/30 = 18 × 7/30 × 7 = 126/210 - Add the two like fractions:
63/210 + 126/210 = 63 + 126/210 = 189/210 - 189/210 simplified gives 9/10
- So, 21/70 + 18/30 = 9/10
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/70+18/30 21/70+36/30 21/70+18/60 63/70+18/30 21/70+54/30 21/70+18/90 21/70+90/30