Add 21/18 and 90/20
1st number: 1 3/18, 2nd number: 4 10/20
21/18 + 90/20 is 17/3.
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,
21/18 = 21 × 10/18 × 10 = 210/180 - Likewise, for the 2nd fraction, since 20 × 9 = 180,
90/20 = 90 × 9/20 × 9 = 810/180 - Add the two like fractions:
210/180 + 810/180 = 210 + 810/180 = 1020/180 - 1020/180 simplified gives 17/3
- So, 21/18 + 90/20 = 17/3
In mixed form: 52/3
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/18+90/20 21/36+90/20 21/18+90/40 63/18+90/20 21/54+90/20 21/18+90/60 21/90+90/20