Add 21/30 and 27/40
21/30 + 27/40 is 11/8.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 30 and 40 is 120
Next, find the equivalent fraction of both fractional numbers with denominator 120 - For the 1st fraction, since 30 × 4 = 120,
21/30 = 21 × 4/30 × 4 = 84/120 - Likewise, for the 2nd fraction, since 40 × 3 = 120,
27/40 = 27 × 3/40 × 3 = 81/120 - Add the two like fractions:
84/120 + 81/120 = 84 + 81/120 = 165/120 - 165/120 simplified gives 11/8
- So, 21/30 + 27/40 = 11/8
In mixed form: 13/8
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/30+27/40 21/30+54/40 21/60+27/40 21/30+27/80 63/30+27/40 21/30+81/40 21/90+27/40