Add 21/54 and 10/42
21/54 + 10/42 is 79/126.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 54 and 42 is 378
Next, find the equivalent fraction of both fractional numbers with denominator 378 - For the 1st fraction, since 54 × 7 = 378,
21/54 = 21 × 7/54 × 7 = 147/378 - Likewise, for the 2nd fraction, since 42 × 9 = 378,
10/42 = 10 × 9/42 × 9 = 90/378 - Add the two like fractions:
147/378 + 90/378 = 147 + 90/378 = 237/378 - 237/378 simplified gives 79/126
- So, 21/54 + 10/42 = 79/126
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/54+10/42 21/54+20/42 21/54+10/84 63/54+10/42 21/54+30/42 21/54+50/42 21/54+70/42