Add 21/84 and 9/8
1st number: 21/84, 2nd number: 1 1/8
21/84 + 9/8 is 11/8.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 84 and 8 is 168
Next, find the equivalent fraction of both fractional numbers with denominator 168 - For the 1st fraction, since 84 × 2 = 168,
21/84 = 21 × 2/84 × 2 = 42/168 - Likewise, for the 2nd fraction, since 8 × 21 = 168,
9/8 = 9 × 21/8 × 21 = 189/168 - Add the two like fractions:
42/168 + 189/168 = 42 + 189/168 = 231/168 - 231/168 simplified gives 11/8
- So, 21/84 + 9/8 = 11/8
In mixed form: 13/8
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/84+9/8 21/84+18/8 21/84+9/16 63/84+9/8 21/84+27/8 21/84+9/24 21/84+45/8 21/84+9/40 21/84+63/8 21/84+9/56