Add 21/40 and 8/81
21/40 + 8/81 is 2021/3240.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 40 and 81 is 3240
Next, find the equivalent fraction of both fractional numbers with denominator 3240 - For the 1st fraction, since 40 × 81 = 3240,
21/40 = 21 × 81/40 × 81 = 1701/3240 - Likewise, for the 2nd fraction, since 81 × 40 = 3240,
8/81 = 8 × 40/81 × 40 = 320/3240 - Add the two like fractions:
1701/3240 + 320/3240 = 1701 + 320/3240 = 2021/3240 - So, 21/40 + 8/81 = 2021/3240
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/40+8/81 21/40+16/81 21/80+8/81 63/40+8/81 21/40+24/81 21/40+40/81 21/40+56/81