Add 21/20 and 45/18
1st number: 1 1/20, 2nd number: 2 9/18
21/20 + 45/18 is 71/20.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 20 and 18 is 180
Next, find the equivalent fraction of both fractional numbers with denominator 180 - For the 1st fraction, since 20 × 9 = 180,
21/20 = 21 × 9/20 × 9 = 189/180 - Likewise, for the 2nd fraction, since 18 × 10 = 180,
45/18 = 45 × 10/18 × 10 = 450/180 - Add the two like fractions:
189/180 + 450/180 = 189 + 450/180 = 639/180 - 639/180 simplified gives 71/20
- So, 21/20 + 45/18 = 71/20
In mixed form: 311/20
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/20+45/18 21/20+90/18 21/40+45/18 21/20+45/36 63/20+45/18 21/60+45/18 21/20+45/54 21/20+45/90