Add 3/40 and 18/21
3/40 + 18/21 is 261/280.
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,
3/40 = 3 × 21/40 × 21 = 63/840 - Likewise, for the 2nd fraction, since 21 × 40 = 840,
18/21 = 18 × 40/21 × 40 = 720/840 - Add the two like fractions:
63/840 + 720/840 = 63 + 720/840 = 783/840 - 783/840 simplified gives 261/280
- So, 3/40 + 18/21 = 261/280
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 6/40+18/21 3/40+36/21 3/80+18/21 3/40+18/42 9/40+18/21 3/40+54/21 3/40+18/63 15/40+18/21 3/40+90/21 21/40+18/21