Add 20/42 and 40/70
20/42 + 40/70 is 22/21.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 70 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 42 × 5 = 210,
20/42 = 20 × 5/42 × 5 = 100/210 - Likewise, for the 2nd fraction, since 70 × 3 = 210,
40/70 = 40 × 3/70 × 3 = 120/210 - Add the two like fractions:
100/210 + 120/210 = 100 + 120/210 = 220/210 - 220/210 simplified gives 22/21
- So, 20/42 + 40/70 = 22/21
In mixed form: 11/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 40/42+40/70 20/42+80/70 20/84+40/70 60/42+40/70