Add 21/40 and 9/90
21/40 + 9/90 is 5/8.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 40 and 90 is 360
Next, find the equivalent fraction of both fractional numbers with denominator 360 - For the 1st fraction, since 40 × 9 = 360,
21/40 = 21 × 9/40 × 9 = 189/360 - Likewise, for the 2nd fraction, since 90 × 4 = 360,
9/90 = 9 × 4/90 × 4 = 36/360 - Add the two like fractions:
189/360 + 36/360 = 189 + 36/360 = 225/360 - 225/360 simplified gives 5/8
- So, 21/40 + 9/90 = 5/8
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/40+9/90 21/40+18/90 21/80+9/90 63/40+9/90 21/40+27/90 21/40+45/90 21/40+63/90