Add 42/21 and 54/20
1st number: 2 0/21, 2nd number: 2 14/20
42/21 + 54/20 is 47/10.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 20 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 21 × 20 = 420,
42/21 = 42 × 20/21 × 20 = 840/420 - Likewise, for the 2nd fraction, since 20 × 21 = 420,
54/20 = 54 × 21/20 × 21 = 1134/420 - Add the two like fractions:
840/420 + 1134/420 = 840 + 1134/420 = 1974/420 - 1974/420 simplified gives 47/10
- So, 42/21 + 54/20 = 47/10
In mixed form: 47/10
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 84/21+54/20 42/21+54/40 42/63+54/20 42/21+54/60