Add 63/42 and 18/8, Solve 1 21/42 + 2 2/8 as a fraction

Add 63/42 and 18/8

1^st number: 1 21/42, 2^nd number: 2 2/8

63/42 + 18/8 is 15/4.

Find the least common denominator or LCM of the two denominators:
LCM of 42 and 8 is 168

Next, find the equivalent fraction of both fractional numbers with denominator 168
For the 1st fraction, since 42 × 4 = 168,
63/42 = 63 × 4/42 × 4 = 252/168
Likewise, for the 2nd fraction, since 8 × 21 = 168,
18/8 = 18 × 21/8 × 21 = 378/168
Add the two like fractions:
252/168 + 378/168 = 252 + 378/168 = 630/168
630/168 simplified gives 15/4
So, 63/42 + 18/8 = 15/4
In mixed form: 33/4

MathStep (Works offline)

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