Add 90/12 and 81/24, Solve 7 6/12 + 3 9/24 as a fraction

Add 90/12 and 81/24

1^st number: 7 6/12, 2^nd number: 3 9/24

90/12 + 81/24 is 87/8.

Find the least common denominator or LCM of the two denominators:
LCM of 12 and 24 is 24

Next, find the equivalent fraction of both fractional numbers with denominator 24
For the 1st fraction, since 12 × 2 = 24,
90/12 = 90 × 2/12 × 2 = 180/24
Likewise, for the 2nd fraction, since 24 × 1 = 24,
81/24 = 81 × 1/24 × 1 = 81/24
Add the two like fractions:
180/24 + 81/24 = 180 + 81/24 = 261/24
261/24 simplified gives 87/8
So, 90/12 + 81/24 = 87/8
In mixed form: 107/8

MathStep (Works offline)

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