Add 4/5 and 21/90
4/5 + 21/90 is 31/30.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 5 and 90 is 90
Next, find the equivalent fraction of both fractional numbers with denominator 90 - For the 1st fraction, since 5 × 18 = 90,
4/5 = 4 × 18/5 × 18 = 72/90 - Likewise, for the 2nd fraction, since 90 × 1 = 90,
21/90 = 21 × 1/90 × 1 = 21/90 - Add the two like fractions:
72/90 + 21/90 = 72 + 21/90 = 93/90 - 93/90 simplified gives 31/30
- So, 4/5 + 21/90 = 31/30
In mixed form: 11/30
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 8/5+21/90 4/5+42/90 4/10+21/90 12/5+21/90 4/5+63/90 4/15+21/90 20/5+21/90 4/25+21/90 28/5+21/90 4/35+21/90