Add 21/15 and 45/10, Solve 1 6/15 + 4 5/10 as a fraction

Add 21/15 and 45/10

1^st number: 1 6/15, 2^nd number: 4 5/10

21/15 + 45/10 is 59/10.

Find the least common denominator or LCM of the two denominators:
LCM of 15 and 10 is 30

Next, find the equivalent fraction of both fractional numbers with denominator 30
For the 1st fraction, since 15 × 2 = 30,
21/15 = 21 × 2/15 × 2 = 42/30
Likewise, for the 2nd fraction, since 10 × 3 = 30,
45/10 = 45 × 3/10 × 3 = 135/30
Add the two like fractions:
42/30 + 135/30 = 42 + 135/30 = 177/30
177/30 simplified gives 59/10
So, 21/15 + 45/10 = 59/10
In mixed form: 59/10

MathStep (Works offline)

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