Add 21/42 and 7/63
21/42 + 7/63 is 11/18.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 63 is 126
Next, find the equivalent fraction of both fractional numbers with denominator 126 - For the 1st fraction, since 42 × 3 = 126,
21/42 = 21 × 3/42 × 3 = 63/126 - Likewise, for the 2nd fraction, since 63 × 2 = 126,
7/63 = 7 × 2/63 × 2 = 14/126 - Add the two like fractions:
63/126 + 14/126 = 63 + 14/126 = 77/126 - 77/126 simplified gives 11/18
- So, 21/42 + 7/63 = 11/18
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 21/42+14/63 21/84+7/63 63/42+7/63 21/42+21/63 21/42+35/63 21/42+49/63