Add 18/40 and 27/21
1st number: 18/40, 2nd number: 1 6/21
18/40 + 27/21 is 243/140.
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,
27/21 = 27 × 40/21 × 40 = 1080/840 - Add the two like fractions:
378/840 + 1080/840 = 378 + 1080/840 = 1458/840 - 1458/840 simplified gives 243/140
- So, 18/40 + 27/21 = 243/140
In mixed form: 1103/140
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 36/40+27/21 18/40+54/21 18/80+27/21 18/40+27/42 54/40+27/21 18/40+81/21 18/40+27/63 90/40+27/21