Add 63/8 and 90/21
1st number: 7 7/8, 2nd number: 4 6/21
63/8 + 90/21 is 681/56.
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,
63/8 = 63 × 21/8 × 21 = 1323/168 - Likewise, for the 2nd fraction, since 21 × 8 = 168,
90/21 = 90 × 8/21 × 8 = 720/168 - Add the two like fractions:
1323/168 + 720/168 = 1323 + 720/168 = 2043/168 - 2043/168 simplified gives 681/56
- So, 63/8 + 90/21 = 681/56
In mixed form: 129/56
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 63/16+90/21 63/8+90/42 63/24+90/21 63/8+90/63 63/40+90/21 63/56+90/21