Add 72/90 and 63/42
1st number: 72/90, 2nd number: 1 21/42
72/90 + 63/42 is 23/10.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 90 and 42 is 630
Next, find the equivalent fraction of both fractional numbers with denominator 630 - For the 1st fraction, since 90 × 7 = 630,
72/90 = 72 × 7/90 × 7 = 504/630 - Likewise, for the 2nd fraction, since 42 × 15 = 630,
63/42 = 63 × 15/42 × 15 = 945/630 - Add the two like fractions:
504/630 + 945/630 = 504 + 945/630 = 1449/630 - 1449/630 simplified gives 23/10
- So, 72/90 + 63/42 = 23/10
In mixed form: 23/10
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 72/90+63/84