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