Add 21/4 and 3/84, Solve 5 1/4 + 3/84 as a fraction

Add 21/4 and 3/84

1^st number: 5 1/4, 2^nd number: 3/84

21/4 + 3/84 is 37/7.

Find the least common denominator or LCM of the two denominators:
LCM of 4 and 84 is 84

Next, find the equivalent fraction of both fractional numbers with denominator 84
For the 1st fraction, since 4 × 21 = 84,
21/4 = 21 × 21/4 × 21 = 441/84
Likewise, for the 2nd fraction, since 84 × 1 = 84,
3/84 = 3 × 1/84 × 1 = 3/84
Add the two like fractions:
441/84 + 3/84 = 441 + 3/84 = 444/84
444/84 simplified gives 37/7
So, 21/4 + 3/84 = 37/7
In mixed form: 52/7

MathStep (Works offline)

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