Add 81/21 and 12/45
1st number: 3 18/21, 2nd number: 12/45
81/21 + 12/45 is 433/105.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 45 is 315
Next, find the equivalent fraction of both fractional numbers with denominator 315 - For the 1st fraction, since 21 × 15 = 315,
81/21 = 81 × 15/21 × 15 = 1215/315 - Likewise, for the 2nd fraction, since 45 × 7 = 315,
12/45 = 12 × 7/45 × 7 = 84/315 - Add the two like fractions:
1215/315 + 84/315 = 1215 + 84/315 = 1299/315 - 1299/315 simplified gives 433/105
- So, 81/21 + 12/45 = 433/105
In mixed form: 413/105
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 81/21+24/45 81/42+12/45 81/21+12/90 81/21+36/45 81/63+12/45 81/21+60/45 81/21+84/45