Add 21/18 and 25/21
1st number: 1 3/18, 2nd number: 1 4/21
21/18 + 25/21 is 33/14.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 18 and 21 is 126
Next, find the equivalent fraction of both fractional numbers with denominator 126 - For the 1st fraction, since 18 × 7 = 126,
21/18 = 21 × 7/18 × 7 = 147/126 - Likewise, for the 2nd fraction, since 21 × 6 = 126,
25/21 = 25 × 6/21 × 6 = 150/126 - Add the two like fractions:
147/126 + 150/126 = 147 + 150/126 = 297/126 - 297/126 simplified gives 33/14
- So, 21/18 + 25/21 = 33/14
In mixed form: 25/14
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/18+25/21 21/18+50/21 21/36+25/21 21/18+25/42 63/18+25/21 21/18+75/21 21/54+25/21 21/18+25/63 21/90+25/21