Add 20/40 and 63/21
1st number: 20/40, 2nd number: 3 0/21
20/40 + 63/21 is 7/2.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 40 and 21 is 840
Next, find the equivalent fraction of both fractional numbers with denominator 840 - For the 1st fraction, since 40 × 21 = 840,
20/40 = 20 × 21/40 × 21 = 420/840 - Likewise, for the 2nd fraction, since 21 × 40 = 840,
63/21 = 63 × 40/21 × 40 = 2520/840 - Add the two like fractions:
420/840 + 2520/840 = 420 + 2520/840 = 2940/840 - 2940/840 simplified gives 7/2
- So, 20/40 + 63/21 = 7/2
In mixed form: 31/2
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 20/80+63/21 20/40+63/42 60/40+63/21