Add 40/8 and 81/21
1st number: 5 0/8, 2nd number: 3 18/21
40/8 + 81/21 is 62/7.
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,
40/8 = 40 × 21/8 × 21 = 840/168 - Likewise, for the 2nd fraction, since 21 × 8 = 168,
81/21 = 81 × 8/21 × 8 = 648/168 - Add the two like fractions:
840/168 + 648/168 = 840 + 648/168 = 1488/168 - 1488/168 simplified gives 62/7
- So, 40/8 + 81/21 = 62/7
In mixed form: 86/7
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 80/8+81/21 40/16+81/21 40/8+81/42 40/24+81/21 40/8+81/63 40/56+81/21