Add 63/42 and 20/90
1st number: 1 21/42, 2nd number: 20/90
63/42 + 20/90 is 31/18.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 90 is 630
Next, find the equivalent fraction of both fractional numbers with denominator 630 - For the 1st fraction, since 42 × 15 = 630,
63/42 = 63 × 15/42 × 15 = 945/630 - Likewise, for the 2nd fraction, since 90 × 7 = 630,
20/90 = 20 × 7/90 × 7 = 140/630 - Add the two like fractions:
945/630 + 140/630 = 945 + 140/630 = 1085/630 - 1085/630 simplified gives 31/18
- So, 63/42 + 20/90 = 31/18
In mixed form: 113/18
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 63/42+40/90 63/84+20/90 63/42+60/90