Add 15/21 and 25/8
1st number: 15/21, 2nd number: 3 1/8
15/21 + 25/8 is 215/56.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 8 is 168
Next, find the equivalent fraction of both fractional numbers with denominator 168 - For the 1st fraction, since 21 × 8 = 168,
15/21 = 15 × 8/21 × 8 = 120/168 - Likewise, for the 2nd fraction, since 8 × 21 = 168,
25/8 = 25 × 21/8 × 21 = 525/168 - Add the two like fractions:
120/168 + 525/168 = 120 + 525/168 = 645/168 - 645/168 simplified gives 215/56
- So, 15/21 + 25/8 = 215/56
In mixed form: 347/56
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 30/21+25/8 15/21+50/8 15/42+25/8 15/21+25/16 45/21+25/8 15/21+75/8 15/63+25/8 15/21+25/24 75/21+25/8 15/21+25/40 15/21+25/56