Add 84/21 and 63/40
1st number: 4 0/21, 2nd number: 1 23/40
84/21 + 63/40 is 223/40.
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,
84/21 = 84 × 40/21 × 40 = 3360/840 - Likewise, for the 2nd fraction, since 40 × 21 = 840,
63/40 = 63 × 21/40 × 21 = 1323/840 - Add the two like fractions:
3360/840 + 1323/840 = 3360 + 1323/840 = 4683/840 - 4683/840 simplified gives 223/40
- So, 84/21 + 63/40 = 223/40
In mixed form: 523/40
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 84/42+63/40 84/21+63/80 84/63+63/40