Add 10/15 and 54/21
1st number: 10/15, 2nd number: 2 12/21
10/15 + 54/21 is 68/21.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 15 and 21 is 105
Next, find the equivalent fraction of both fractional numbers with denominator 105 - For the 1st fraction, since 15 × 7 = 105,
10/15 = 10 × 7/15 × 7 = 70/105 - Likewise, for the 2nd fraction, since 21 × 5 = 105,
54/21 = 54 × 5/21 × 5 = 270/105 - Add the two like fractions:
70/105 + 270/105 = 70 + 270/105 = 340/105 - 340/105 simplified gives 68/21
- So, 10/15 + 54/21 = 68/21
In mixed form: 35/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 20/15+54/21 10/30+54/21 10/15+54/42 30/15+54/21 10/45+54/21 10/15+54/63 50/15+54/21 10/75+54/21 70/15+54/21