Add 21/42 and 56/45
1st number: 21/42, 2nd number: 1 11/45
21/42 + 56/45 is 157/90.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 45 is 630
Next, find the equivalent fraction of both fractional numbers with denominator 630 - For the 1st fraction, since 42 × 15 = 630,
21/42 = 21 × 15/42 × 15 = 315/630 - Likewise, for the 2nd fraction, since 45 × 14 = 630,
56/45 = 56 × 14/45 × 14 = 784/630 - Add the two like fractions:
315/630 + 784/630 = 315 + 784/630 = 1099/630 - 1099/630 simplified gives 157/90
- So, 21/42 + 56/45 = 157/90
In mixed form: 167/90
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 21/84+56/45 21/42+56/90 63/42+56/45