Add 20/8 and 63/21
1st number: 2 4/8, 2nd number: 3 0/21
20/8 + 63/21 is 11/2.
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,
63/21 = 63 × 8/21 × 8 = 504/168 - Add the two like fractions:
420/168 + 504/168 = 420 + 504/168 = 924/168 - 924/168 simplified gives 11/2
- So, 20/8 + 63/21 = 11/2
In mixed form: 51/2
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 40/8+63/21 20/16+63/21 20/8+63/42 60/8+63/21 20/24+63/21 20/40+63/21 20/56+63/21