Add 42/21 and 45/12
1st number: 2 0/21, 2nd number: 3 9/12
42/21 + 45/12 is 23/4.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 12 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 21 × 4 = 84,
42/21 = 42 × 4/21 × 4 = 168/84 - Likewise, for the 2nd fraction, since 12 × 7 = 84,
45/12 = 45 × 7/12 × 7 = 315/84 - Add the two like fractions:
168/84 + 315/84 = 168 + 315/84 = 483/84 - 483/84 simplified gives 23/4
- So, 42/21 + 45/12 = 23/4
In mixed form: 53/4
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 84/21+45/12 42/21+90/12 42/21+45/24 42/63+45/12 42/21+45/36 42/21+45/60 42/21+45/84