Add 21/20 and 40/42
1st number: 1 1/20, 2nd number: 40/42
21/20 + 40/42 is 841/420.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 20 and 42 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 20 × 21 = 420,
21/20 = 21 × 21/20 × 21 = 441/420 - Likewise, for the 2nd fraction, since 42 × 10 = 420,
40/42 = 40 × 10/42 × 10 = 400/420 - Add the two like fractions:
441/420 + 400/420 = 441 + 400/420 = 841/420 - So, 21/20 + 40/42 = 841/420
In mixed form: 21/420
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/20+40/42 21/20+80/42 21/40+40/42 21/20+40/84 63/20+40/42 21/60+40/42