Add 81/42 and 5/20
1st number: 1 39/42, 2nd number: 5/20
81/42 + 5/20 is 61/28.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 20 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 42 × 10 = 420,
81/42 = 81 × 10/42 × 10 = 810/420 - Likewise, for the 2nd fraction, since 20 × 21 = 420,
5/20 = 5 × 21/20 × 21 = 105/420 - Add the two like fractions:
810/420 + 105/420 = 810 + 105/420 = 915/420 - 915/420 simplified gives 61/28
- So, 81/42 + 5/20 = 61/28
In mixed form: 25/28
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 81/42+10/20 81/84+5/20 81/42+5/40 81/42+15/20 81/42+5/60 81/42+25/20 81/42+35/20