Add 1/21 and 28/25, Solve 1/21 + 1 3/25 as a fraction

Add 1/21 and 28/25

1^st number: 1/21, 2^nd number: 1 3/25

1/21 + 28/25 is 613/525.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 25 is 525

Next, find the equivalent fraction of both fractional numbers with denominator 525
For the 1st fraction, since 21 × 25 = 525,
1/21 = 1 × 25/21 × 25 = 25/525
Likewise, for the 2nd fraction, since 25 × 21 = 525,
28/25 = 28 × 21/25 × 21 = 588/525
Add the two like fractions:
25/525 + 588/525 = 25 + 588/525 = 613/525
So, 1/21 + 28/25 = 613/525
In mixed form: 188/525

MathStep (Works offline)

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