Add 21/28 and 45/18
1st number: 21/28, 2nd number: 2 9/18
21/28 + 45/18 is 13/4.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 28 and 18 is 252
Next, find the equivalent fraction of both fractional numbers with denominator 252 - For the 1st fraction, since 28 × 9 = 252,
21/28 = 21 × 9/28 × 9 = 189/252 - Likewise, for the 2nd fraction, since 18 × 14 = 252,
45/18 = 45 × 14/18 × 14 = 630/252 - Add the two like fractions:
189/252 + 630/252 = 189 + 630/252 = 819/252 - 819/252 simplified gives 13/4
- So, 21/28 + 45/18 = 13/4
In mixed form: 31/4
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/28+45/18 21/28+90/18 21/56+45/18 21/28+45/36 63/28+45/18 21/84+45/18 21/28+45/54 21/28+45/90