Add 20/8 and 16/21
1st number: 2 4/8, 2nd number: 16/21
20/8 + 16/21 is 137/42.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 8 and 21 is 168
Next, find the equivalent fraction of both fractional numbers with denominator 168 - For the 1st fraction, since 8 × 21 = 168,
20/8 = 20 × 21/8 × 21 = 420/168 - Likewise, for the 2nd fraction, since 21 × 8 = 168,
16/21 = 16 × 8/21 × 8 = 128/168 - Add the two like fractions:
420/168 + 128/168 = 420 + 128/168 = 548/168 - 548/168 simplified gives 137/42
- So, 20/8 + 16/21 = 137/42
In mixed form: 311/42
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 40/8+16/21 20/8+32/21 20/16+16/21 20/8+16/42 60/8+16/21 20/8+48/21 20/24+16/21 20/8+16/63 20/8+80/21 20/40+16/21 20/56+16/21