Add 18/21 and 3/8
18/21 + 3/8 is 69/56.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 8 is 168
Next, find the equivalent fraction of both fractional numbers with denominator 168 - For the 1st fraction, since 21 × 8 = 168,
18/21 = 18 × 8/21 × 8 = 144/168 - Likewise, for the 2nd fraction, since 8 × 21 = 168,
3/8 = 3 × 21/8 × 21 = 63/168 - Add the two like fractions:
144/168 + 63/168 = 144 + 63/168 = 207/168 - 207/168 simplified gives 69/56
- So, 18/21 + 3/8 = 69/56
In mixed form: 113/56
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 36/21+3/8 18/21+6/8 18/42+3/8 18/21+3/16 54/21+3/8 18/21+9/8 18/63+3/8 18/21+3/24 90/21+3/8 18/21+15/8 18/21+3/40 18/21+21/8 18/21+3/56