Add 63/21 and 70/40
1st number: 3 0/21, 2nd number: 1 30/40
63/21 + 70/40 is 19/4.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 40 is 840
Next, find the equivalent fraction of both fractional numbers with denominator 840 - For the 1st fraction, since 21 × 40 = 840,
63/21 = 63 × 40/21 × 40 = 2520/840 - Likewise, for the 2nd fraction, since 40 × 21 = 840,
70/40 = 70 × 21/40 × 21 = 1470/840 - Add the two like fractions:
2520/840 + 1470/840 = 2520 + 1470/840 = 3990/840 - 3990/840 simplified gives 19/4
- So, 63/21 + 70/40 = 19/4
In mixed form: 43/4
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 63/42+70/40 63/21+70/80