Add 21/45 and 72/18
1st number: 21/45, 2nd number: 4 0/18
21/45 + 72/18 is 67/15.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 45 and 18 is 90
Next, find the equivalent fraction of both fractional numbers with denominator 90 - For the 1st fraction, since 45 × 2 = 90,
21/45 = 21 × 2/45 × 2 = 42/90 - Likewise, for the 2nd fraction, since 18 × 5 = 90,
72/18 = 72 × 5/18 × 5 = 360/90 - Add the two like fractions:
42/90 + 360/90 = 42 + 360/90 = 402/90 - 402/90 simplified gives 67/15
- So, 21/45 + 72/18 = 67/15
In mixed form: 47/15
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/45+72/18 21/90+72/18 21/45+72/36 63/45+72/18 21/45+72/54 21/45+72/90