Add 45/30 and 72/21
1st number: 1 15/30, 2nd number: 3 9/21
45/30 + 72/21 is 69/14.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 30 and 21 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 30 × 7 = 210,
45/30 = 45 × 7/30 × 7 = 315/210 - Likewise, for the 2nd fraction, since 21 × 10 = 210,
72/21 = 72 × 10/21 × 10 = 720/210 - Add the two like fractions:
315/210 + 720/210 = 315 + 720/210 = 1035/210 - 1035/210 simplified gives 69/14
- So, 45/30 + 72/21 = 69/14
In mixed form: 413/14
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 90/30+72/21 45/60+72/21 45/30+72/42 45/90+72/21 45/30+72/63