Add 30/9 and 21/7, Solve 3 3/9 + 3 0/7 as a fraction

Add 30/9 and 21/7

1^st number: 3 3/9, 2^nd number: 3 0/7

30/9 + 21/7 is 19/3.

Find the least common denominator or LCM of the two denominators:
LCM of 9 and 7 is 63

Next, find the equivalent fraction of both fractional numbers with denominator 63
For the 1st fraction, since 9 × 7 = 63,
30/9 = 30 × 7/9 × 7 = 210/63
Likewise, for the 2nd fraction, since 7 × 9 = 63,
21/7 = 21 × 9/7 × 9 = 189/63
Add the two like fractions:
210/63 + 189/63 = 210 + 189/63 = 399/63
399/63 simplified gives 19/3
So, 30/9 + 21/7 = 19/3
In mixed form: 61/3

MathStep (Works offline)

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