Add 40/8 and 12/21
1st number: 5 0/8, 2nd number: 12/21
40/8 + 12/21 is 39/7.
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,
12/21 = 12 × 8/21 × 8 = 96/168 - Add the two like fractions:
840/168 + 96/168 = 840 + 96/168 = 936/168 - 936/168 simplified gives 39/7
- So, 40/8 + 12/21 = 39/7
In mixed form: 54/7
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 80/8+12/21 40/8+24/21 40/16+12/21 40/8+12/42 40/8+36/21 40/24+12/21 40/8+12/63 40/8+60/21 40/8+84/21 40/56+12/21