Add 7/30 and 8/21
7/30 + 8/21 is 43/70.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 30 and 21 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 30 × 7 = 210,
7/30 = 7 × 7/30 × 7 = 49/210 - Likewise, for the 2nd fraction, since 21 × 10 = 210,
8/21 = 8 × 10/21 × 10 = 80/210 - Add the two like fractions:
49/210 + 80/210 = 49 + 80/210 = 129/210 - 129/210 simplified gives 43/70
- So, 7/30 + 8/21 = 43/70
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 14/30+8/21 7/30+16/21 7/60+8/21 7/30+8/42 21/30+8/21 7/30+24/21 7/90+8/21 7/30+8/63 35/30+8/21 7/30+40/21 49/30+8/21 7/30+56/21