Add 45/72 and 21/20
1st number: 45/72, 2nd number: 1 1/20
45/72 + 21/20 is 67/40.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 72 and 20 is 360
Next, find the equivalent fraction of both fractional numbers with denominator 360 - For the 1st fraction, since 72 × 5 = 360,
45/72 = 45 × 5/72 × 5 = 225/360 - Likewise, for the 2nd fraction, since 20 × 18 = 360,
21/20 = 21 × 18/20 × 18 = 378/360 - Add the two like fractions:
225/360 + 378/360 = 225 + 378/360 = 603/360 - 603/360 simplified gives 67/40
- So, 45/72 + 21/20 = 67/40
In mixed form: 127/40
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 90/72+21/20 45/72+42/20 45/72+21/40 45/72+63/20 45/72+21/60