Add 21/2 and 15/21
1st number: 10 1/2, 2nd number: 15/21
21/2 + 15/21 is 157/14.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 2 and 21 is 42
Next, find the equivalent fraction of both fractional numbers with denominator 42 - For the 1st fraction, since 2 × 21 = 42,
21/2 = 21 × 21/2 × 21 = 441/42 - Likewise, for the 2nd fraction, since 21 × 2 = 42,
15/21 = 15 × 2/21 × 2 = 30/42 - Add the two like fractions:
441/42 + 30/42 = 441 + 30/42 = 471/42 - 471/42 simplified gives 157/14
- So, 21/2 + 15/21 = 157/14
In mixed form: 113/14
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/2+15/21 21/2+30/21 21/4+15/21 21/2+15/42 63/2+15/21 21/2+45/21 21/6+15/21 21/2+15/63 21/2+75/21 21/10+15/21 21/14+15/21