Add 21/64 and 28/9, Solve 21/64 + 3 1/9 as a fraction

Add 21/64 and 28/9

1^st number: 21/64, 2^nd number: 3 1/9

21/64 + 28/9 is 1981/576.

Find the least common denominator or LCM of the two denominators:
LCM of 64 and 9 is 576

Next, find the equivalent fraction of both fractional numbers with denominator 576
For the 1st fraction, since 64 × 9 = 576,
21/64 = 21 × 9/64 × 9 = 189/576
Likewise, for the 2nd fraction, since 9 × 64 = 576,
28/9 = 28 × 64/9 × 64 = 1792/576
Add the two like fractions:
189/576 + 1792/576 = 189 + 1792/576 = 1981/576
So, 21/64 + 28/9 = 1981/576
In mixed form: 3253/576

MathStep (Works offline)

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