Add 21/35 and 90/18, Solve 21/35 + 5 0/18 as a fraction

Add 21/35 and 90/18

1^st number: 21/35, 2^nd number: 5 0/18

21/35 + 90/18 is 28/5.

Find the least common denominator or LCM of the two denominators:
LCM of 35 and 18 is 630

Next, find the equivalent fraction of both fractional numbers with denominator 630
For the 1st fraction, since 35 × 18 = 630,
21/35 = 21 × 18/35 × 18 = 378/630
Likewise, for the 2nd fraction, since 18 × 35 = 630,
90/18 = 90 × 35/18 × 35 = 3150/630
Add the two like fractions:
378/630 + 3150/630 = 378 + 3150/630 = 3528/630
3528/630 simplified gives 28/5
So, 21/35 + 90/18 = 28/5
In mixed form: 53/5

MathStep (Works offline)

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