Add 40/21 and 70/40
1st number: 1 19/21, 2nd number: 1 30/40
40/21 + 70/40 is 307/84.
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,
40/21 = 40 × 40/21 × 40 = 1600/840 - Likewise, for the 2nd fraction, since 40 × 21 = 840,
70/40 = 70 × 21/40 × 21 = 1470/840 - Add the two like fractions:
1600/840 + 1470/840 = 1600 + 1470/840 = 3070/840 - 3070/840 simplified gives 307/84
- So, 40/21 + 70/40 = 307/84
In mixed form: 355/84
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 80/21+70/40 40/42+70/40 40/21+70/80 40/63+70/40