Add 10/21 and 9/40
10/21 + 9/40 is 589/840.
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,
10/21 = 10 × 40/21 × 40 = 400/840 - Likewise, for the 2nd fraction, since 40 × 21 = 840,
9/40 = 9 × 21/40 × 21 = 189/840 - Add the two like fractions:
400/840 + 189/840 = 400 + 189/840 = 589/840 - So, 10/21 + 9/40 = 589/840
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 20/21+9/40 10/21+18/40 10/42+9/40 10/21+9/80 30/21+9/40 10/21+27/40 10/63+9/40 50/21+9/40 10/21+45/40 70/21+9/40 10/21+63/40