Add 18/21 and 70/40
1st number: 18/21, 2nd number: 1 30/40
18/21 + 70/40 is 73/28.
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,
18/21 = 18 × 40/21 × 40 = 720/840 - Likewise, for the 2nd fraction, since 40 × 21 = 840,
70/40 = 70 × 21/40 × 21 = 1470/840 - Add the two like fractions:
720/840 + 1470/840 = 720 + 1470/840 = 2190/840 - 2190/840 simplified gives 73/28
- So, 18/21 + 70/40 = 73/28
In mixed form: 217/28
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 36/21+70/40 18/42+70/40 18/21+70/80 54/21+70/40 18/63+70/40 90/21+70/40