Add 20/81 and 42/40
1st number: 20/81, 2nd number: 1 2/40
20/81 + 42/40 is 2101/1620.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 81 and 40 is 3240
Next, find the equivalent fraction of both fractional numbers with denominator 3240 - For the 1st fraction, since 81 × 40 = 3240,
20/81 = 20 × 40/81 × 40 = 800/3240 - Likewise, for the 2nd fraction, since 40 × 81 = 3240,
42/40 = 42 × 81/40 × 81 = 3402/3240 - Add the two like fractions:
800/3240 + 3402/3240 = 800 + 3402/3240 = 4202/3240 - 4202/3240 simplified gives 2101/1620
- So, 20/81 + 42/40 = 2101/1620
In mixed form: 1481/1620
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 40/81+42/40 20/81+84/40 20/81+42/80 60/81+42/40