Add 81/63 and 28/40, Solve 1 18/63 + 28/40 as a fraction

Add 81/63 and 28/40

1^st number: 1 18/63, 2^nd number: 28/40

81/63 + 28/40 is 139/70.

Find the least common denominator or LCM of the two denominators:
LCM of 63 and 40 is 2520

Next, find the equivalent fraction of both fractional numbers with denominator 2520
For the 1st fraction, since 63 × 40 = 2520,
81/63 = 81 × 40/63 × 40 = 3240/2520
Likewise, for the 2nd fraction, since 40 × 63 = 2520,
28/40 = 28 × 63/40 × 63 = 1764/2520
Add the two like fractions:
3240/2520 + 1764/2520 = 3240 + 1764/2520 = 5004/2520
5004/2520 simplified gives 139/70
So, 81/63 + 28/40 = 139/70
In mixed form: 169/70

MathStep (Works offline)

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