Add 21/4 and 15/63, Solve 5 1/4 + 15/63 as a fraction

Add 21/4 and 15/63

1^st number: 5 1/4, 2^nd number: 15/63

21/4 + 15/63 is 461/84.

Find the least common denominator or LCM of the two denominators:
LCM of 4 and 63 is 252

Next, find the equivalent fraction of both fractional numbers with denominator 252
For the 1st fraction, since 4 × 63 = 252,
21/4 = 21 × 63/4 × 63 = 1323/252
Likewise, for the 2nd fraction, since 63 × 4 = 252,
15/63 = 15 × 4/63 × 4 = 60/252
Add the two like fractions:
1323/252 + 60/252 = 1323 + 60/252 = 1383/252
1383/252 simplified gives 461/84
So, 21/4 + 15/63 = 461/84
In mixed form: 541/84

MathStep (Works offline)

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