Add 12/21 and 30/81
12/21 + 30/81 is 178/189.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 81 is 567
Next, find the equivalent fraction of both fractional numbers with denominator 567 - For the 1st fraction, since 21 × 27 = 567,
12/21 = 12 × 27/21 × 27 = 324/567 - Likewise, for the 2nd fraction, since 81 × 7 = 567,
30/81 = 30 × 7/81 × 7 = 210/567 - Add the two like fractions:
324/567 + 210/567 = 324 + 210/567 = 534/567 - 534/567 simplified gives 178/189
- So, 12/21 + 30/81 = 178/189
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 24/21+30/81 12/21+60/81 12/42+30/81 36/21+30/81 12/21+90/81 12/63+30/81 60/21+30/81 84/21+30/81