Add 21/7 and 54/8
1st number: 3 0/7, 2nd number: 6 6/8
21/7 + 54/8 is 39/4.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 7 and 8 is 56
Next, find the equivalent fraction of both fractional numbers with denominator 56 - For the 1st fraction, since 7 × 8 = 56,
21/7 = 21 × 8/7 × 8 = 168/56 - Likewise, for the 2nd fraction, since 8 × 7 = 56,
54/8 = 54 × 7/8 × 7 = 378/56 - Add the two like fractions:
168/56 + 378/56 = 168 + 378/56 = 546/56 - 546/56 simplified gives 39/4
- So, 21/7 + 54/8 = 39/4
In mixed form: 93/4
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/7+54/8 21/14+54/8 21/7+54/16 63/7+54/8 21/7+54/24 21/35+54/8 21/7+54/40 21/49+54/8 21/7+54/56