Add 70/21 and 63/45
1st number: 3 7/21, 2nd number: 1 18/45
70/21 + 63/45 is 71/15.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 45 is 315
Next, find the equivalent fraction of both fractional numbers with denominator 315 - For the 1st fraction, since 21 × 15 = 315,
70/21 = 70 × 15/21 × 15 = 1050/315 - Likewise, for the 2nd fraction, since 45 × 7 = 315,
63/45 = 63 × 7/45 × 7 = 441/315 - Add the two like fractions:
1050/315 + 441/315 = 1050 + 441/315 = 1491/315 - 1491/315 simplified gives 71/15
- So, 70/21 + 63/45 = 71/15
In mixed form: 411/15
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 70/42+63/45 70/21+63/90 70/63+63/45