Add 30/21 and 72/80
1st number: 1 9/21, 2nd number: 72/80
30/21 + 72/80 is 163/70.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 80 is 1680
Next, find the equivalent fraction of both fractional numbers with denominator 1680 - For the 1st fraction, since 21 × 80 = 1680,
30/21 = 30 × 80/21 × 80 = 2400/1680 - Likewise, for the 2nd fraction, since 80 × 21 = 1680,
72/80 = 72 × 21/80 × 21 = 1512/1680 - Add the two like fractions:
2400/1680 + 1512/1680 = 2400 + 1512/1680 = 3912/1680 - 3912/1680 simplified gives 163/70
- So, 30/21 + 72/80 = 163/70
In mixed form: 223/70
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 60/21+72/80 30/42+72/80 90/21+72/80 30/63+72/80