Add 30/70 and 40/12
1st number: 30/70, 2nd number: 3 4/12
30/70 + 40/12 is 79/21.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 70 and 12 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 70 × 6 = 420,
30/70 = 30 × 6/70 × 6 = 180/420 - Likewise, for the 2nd fraction, since 12 × 35 = 420,
40/12 = 40 × 35/12 × 35 = 1400/420 - Add the two like fractions:
180/420 + 1400/420 = 180 + 1400/420 = 1580/420 - 1580/420 simplified gives 79/21
- So, 30/70 + 40/12 = 79/21
In mixed form: 316/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 60/70+40/12 30/70+80/12 30/70+40/24 90/70+40/12 30/70+40/36 30/70+40/60 30/70+40/84