Add 18/20 and 12/42
18/20 + 12/42 is 83/70.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 20 and 42 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 20 × 21 = 420,
18/20 = 18 × 21/20 × 21 = 378/420 - Likewise, for the 2nd fraction, since 42 × 10 = 420,
12/42 = 12 × 10/42 × 10 = 120/420 - Add the two like fractions:
378/420 + 120/420 = 378 + 120/420 = 498/420 - 498/420 simplified gives 83/70
- So, 18/20 + 12/42 = 83/70
In mixed form: 113/70
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 36/20+12/42 18/20+24/42 18/40+12/42 18/20+12/84 54/20+12/42 18/20+36/42 18/60+12/42 90/20+12/42 18/20+60/42 18/20+84/42