Add 21/42 and 42/8
1st number: 21/42, 2nd number: 5 2/8
21/42 + 42/8 is 23/4.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 8 is 168
Next, find the equivalent fraction of both fractional numbers with denominator 168 - For the 1st fraction, since 42 × 4 = 168,
21/42 = 21 × 4/42 × 4 = 84/168 - Likewise, for the 2nd fraction, since 8 × 21 = 168,
42/8 = 42 × 21/8 × 21 = 882/168 - Add the two like fractions:
84/168 + 882/168 = 84 + 882/168 = 966/168 - 966/168 simplified gives 23/4
- So, 21/42 + 42/8 = 23/4
In mixed form: 53/4
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 21/42+84/8 21/84+42/8 21/42+42/16 63/42+42/8 21/42+42/24 21/42+42/40 21/42+42/56