Add 7/8 and 30/21
1st number: 7/8, 2nd number: 1 9/21
7/8 + 30/21 is 129/56.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 8 and 21 is 168
Next, find the equivalent fraction of both fractional numbers with denominator 168 - For the 1st fraction, since 8 × 21 = 168,
7/8 = 7 × 21/8 × 21 = 147/168 - Likewise, for the 2nd fraction, since 21 × 8 = 168,
30/21 = 30 × 8/21 × 8 = 240/168 - Add the two like fractions:
147/168 + 240/168 = 147 + 240/168 = 387/168 - 387/168 simplified gives 129/56
- So, 7/8 + 30/21 = 129/56
In mixed form: 217/56
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 14/8+30/21 7/8+60/21 7/16+30/21 7/8+30/42 21/8+30/21 7/8+90/21 7/24+30/21 7/8+30/63 35/8+30/21 7/40+30/21 49/8+30/21 7/56+30/21