Add 36/21 and 12/27, Solve 1 15/21 + 12/27 as a fraction

Add 36/21 and 12/27

1^st number: 1 15/21, 2^nd number: 12/27

36/21 + 12/27 is 136/63.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 27 is 189

Next, find the equivalent fraction of both fractional numbers with denominator 189
For the 1st fraction, since 21 × 9 = 189,
36/21 = 36 × 9/21 × 9 = 324/189
Likewise, for the 2nd fraction, since 27 × 7 = 189,
12/27 = 12 × 7/27 × 7 = 84/189
Add the two like fractions:
324/189 + 84/189 = 324 + 84/189 = 408/189
408/189 simplified gives 136/63
So, 36/21 + 12/27 = 136/63
In mixed form: 210/63

MathStep (Works offline)

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