Add 72/18 and 45/20
1st number: 4 0/18, 2nd number: 2 5/20
72/18 + 45/20 is 25/4.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 18 and 20 is 180
Next, find the equivalent fraction of both fractional numbers with denominator 180 - For the 1st fraction, since 18 × 10 = 180,
72/18 = 72 × 10/18 × 10 = 720/180 - Likewise, for the 2nd fraction, since 20 × 9 = 180,
45/20 = 45 × 9/20 × 9 = 405/180 - Add the two like fractions:
720/180 + 405/180 = 720 + 405/180 = 1125/180 - 1125/180 simplified gives 25/4
- So, 72/18 + 45/20 = 25/4
In mixed form: 61/4
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 72/18+90/20 72/36+45/20 72/18+45/40 72/54+45/20 72/18+45/60 72/90+45/20