Add 21/30 and 18/70
21/30 + 18/70 is 67/70.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 30 and 70 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 70 × 3 = 210,
18/70 = 18 × 3/70 × 3 = 54/210 - Add the two like fractions:
147/210 + 54/210 = 147 + 54/210 = 201/210 - 201/210 simplified gives 67/70
- So, 21/30 + 18/70 = 67/70
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/30+18/70 21/30+36/70 21/60+18/70 63/30+18/70 21/30+54/70 21/90+18/70 21/30+90/70