Add 4/21 and 84/40, Solve 4/21 + 2 4/40 as a fraction

Add 4/21 and 84/40

1^st number: 4/21, 2^nd number: 2 4/40

4/21 + 84/40 is 481/210.

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,
4/21 = 4 × 40/21 × 40 = 160/840
Likewise, for the 2nd fraction, since 40 × 21 = 840,
84/40 = 84 × 21/40 × 21 = 1764/840
Add the two like fractions:
160/840 + 1764/840 = 160 + 1764/840 = 1924/840
1924/840 simplified gives 481/210
So, 4/21 + 84/40 = 481/210
In mixed form: 261/210

MathStep (Works offline)

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