Add 21/42 and 45/16, Solve 21/42 + 2 13/16 as a fraction

Add 21/42 and 45/16

1^st number: 21/42, 2^nd number: 2 13/16

21/42 + 45/16 is 53/16.

Find the least common denominator or LCM of the two denominators:
LCM of 42 and 16 is 336

Next, find the equivalent fraction of both fractional numbers with denominator 336
For the 1st fraction, since 42 × 8 = 336,
21/42 = 21 × 8/42 × 8 = 168/336
Likewise, for the 2nd fraction, since 16 × 21 = 336,
45/16 = 45 × 21/16 × 21 = 945/336
Add the two like fractions:
168/336 + 945/336 = 168 + 945/336 = 1113/336
1113/336 simplified gives 53/16
So, 21/42 + 45/16 = 53/16
In mixed form: 35/16

MathStep (Works offline)

Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad