Add 45/12 and 27/80, Solve 3 9/12 + 27/80 as a fraction

Add 45/12 and 27/80

1^st number: 3 9/12, 2^nd number: 27/80

45/12 + 27/80 is 327/80.

Find the least common denominator or LCM of the two denominators:
LCM of 12 and 80 is 240

Next, find the equivalent fraction of both fractional numbers with denominator 240
For the 1st fraction, since 12 × 20 = 240,
45/12 = 45 × 20/12 × 20 = 900/240
Likewise, for the 2nd fraction, since 80 × 3 = 240,
27/80 = 27 × 3/80 × 3 = 81/240
Add the two like fractions:
900/240 + 81/240 = 900 + 81/240 = 981/240
981/240 simplified gives 327/80
So, 45/12 + 27/80 = 327/80
In mixed form: 47/80

MathStep (Works offline)

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