Add 40/42 and 8/21
40/42 + 8/21 is 4/3.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 21 is 42
Next, find the equivalent fraction of both fractional numbers with denominator 42 - For the 1st fraction, since 42 × 1 = 42,
40/42 = 40 × 1/42 × 1 = 40/42 - Likewise, for the 2nd fraction, since 21 × 2 = 42,
8/21 = 8 × 2/21 × 2 = 16/42 - Add the two like fractions:
40/42 + 16/42 = 40 + 16/42 = 56/42 - 56/42 simplified gives 4/3
- So, 40/42 + 8/21 = 4/3
In mixed form: 11/3
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 80/42+8/21 40/42+16/21 40/84+8/21 40/42+8/42 40/42+24/21 40/42+8/63 40/42+40/21 40/42+56/21