Add 25/8 and 15/21
1st number: 3 1/8, 2nd number: 15/21
25/8 + 15/21 is 215/56.
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,
25/8 = 25 × 21/8 × 21 = 525/168 - Likewise, for the 2nd fraction, since 21 × 8 = 168,
15/21 = 15 × 8/21 × 8 = 120/168 - Add the two like fractions:
525/168 + 120/168 = 525 + 120/168 = 645/168 - 645/168 simplified gives 215/56
- So, 25/8 + 15/21 = 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: 50/8+15/21 25/8+30/21 25/16+15/21 25/8+15/42 75/8+15/21 25/8+45/21 25/24+15/21 25/8+15/63 25/8+75/21 25/40+15/21 25/56+15/21