Add 30/70 and 81/42
1st number: 30/70, 2nd number: 1 39/42
30/70 + 81/42 is 33/14.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 70 and 42 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 70 × 3 = 210,
30/70 = 30 × 3/70 × 3 = 90/210 - Likewise, for the 2nd fraction, since 42 × 5 = 210,
81/42 = 81 × 5/42 × 5 = 405/210 - Add the two like fractions:
90/210 + 405/210 = 90 + 405/210 = 495/210 - 495/210 simplified gives 33/14
- So, 30/70 + 81/42 = 33/14
In mixed form: 25/14
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 60/70+81/42 30/70+81/84 90/70+81/42