Add 28/21 and 8/80, Solve 1 7/21 + 8/80 as a fraction

Add 28/21 and 8/80

1^st number: 1 7/21, 2^nd number: 8/80

28/21 + 8/80 is 43/30.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 80 is 1680

Next, find the equivalent fraction of both fractional numbers with denominator 1680
For the 1st fraction, since 21 × 80 = 1680,
28/21 = 28 × 80/21 × 80 = 2240/1680
Likewise, for the 2nd fraction, since 80 × 21 = 1680,
8/80 = 8 × 21/80 × 21 = 168/1680
Add the two like fractions:
2240/1680 + 168/1680 = 2240 + 168/1680 = 2408/1680
2408/1680 simplified gives 43/30
So, 28/21 + 8/80 = 43/30
In mixed form: 113/30

MathStep (Works offline)

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