Add 10/21 and 45/40, Solve 10/21 + 1 5/40 as a fraction

Add 10/21 and 45/40

1^st number: 10/21, 2^nd number: 1 5/40

10/21 + 45/40 is 269/168.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 40 is 840

Next, find the equivalent fraction of both fractional numbers with denominator 840
For the 1st fraction, since 21 × 40 = 840,
10/21 = 10 × 40/21 × 40 = 400/840
Likewise, for the 2nd fraction, since 40 × 21 = 840,
45/40 = 45 × 21/40 × 21 = 945/840
Add the two like fractions:
400/840 + 945/840 = 400 + 945/840 = 1345/840
1345/840 simplified gives 269/168
So, 10/21 + 45/40 = 269/168
In mixed form: 1101/168

MathStep (Works offline)

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