Add 21/8 and 10/40, Solve 2 5/8 + 10/40 as a fraction

Add 21/8 and 10/40

1^st number: 2 5/8, 2^nd number: 10/40

21/8 + 10/40 is 23/8.

Find the least common denominator or LCM of the two denominators:
LCM of 8 and 40 is 40

Next, find the equivalent fraction of both fractional numbers with denominator 40
For the 1st fraction, since 8 × 5 = 40,
21/8 = 21 × 5/8 × 5 = 105/40
Likewise, for the 2nd fraction, since 40 × 1 = 40,
10/40 = 10 × 1/40 × 1 = 10/40
Add the two like fractions:
105/40 + 10/40 = 105 + 10/40 = 115/40
115/40 simplified gives 23/8
So, 21/8 + 10/40 = 23/8
In mixed form: 27/8

MathStep (Works offline)

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