Add 7/4 and 21/42
1st number: 1 3/4, 2nd number: 21/42
7/4 + 21/42 is 9/4.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 4 and 42 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 4 × 21 = 84,
7/4 = 7 × 21/4 × 21 = 147/84 - Likewise, for the 2nd fraction, since 42 × 2 = 84,
21/42 = 21 × 2/42 × 2 = 42/84 - Add the two like fractions:
147/84 + 42/84 = 147 + 42/84 = 189/84 - 189/84 simplified gives 9/4
- So, 7/4 + 21/42 = 9/4
In mixed form: 21/4
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 14/4+21/42 7/8+21/42 7/4+21/84 21/4+21/42 7/4+63/42 7/12+21/42 35/4+21/42 7/20+21/42 49/4+21/42 7/28+21/42