Add 18/40 and 81/21
1st number: 18/40, 2nd number: 3 18/21
18/40 + 81/21 is 603/140.
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,
18/40 = 18 × 21/40 × 21 = 378/840 - Likewise, for the 2nd fraction, since 21 × 40 = 840,
81/21 = 81 × 40/21 × 40 = 3240/840 - Add the two like fractions:
378/840 + 3240/840 = 378 + 3240/840 = 3618/840 - 3618/840 simplified gives 603/140
- So, 18/40 + 81/21 = 603/140
In mixed form: 443/140
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 36/40+81/21 18/80+81/21 18/40+81/42 54/40+81/21 18/40+81/63 90/40+81/21