Add 21/42 and 90/18
1st number: 21/42, 2nd number: 5 0/18
21/42 + 90/18 is 11/2.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 18 is 126
Next, find the equivalent fraction of both fractional numbers with denominator 126 - For the 1st fraction, since 42 × 3 = 126,
21/42 = 21 × 3/42 × 3 = 63/126 - Likewise, for the 2nd fraction, since 18 × 7 = 126,
90/18 = 90 × 7/18 × 7 = 630/126 - Add the two like fractions:
63/126 + 630/126 = 63 + 630/126 = 693/126 - 693/126 simplified gives 11/2
- So, 21/42 + 90/18 = 11/2
In mixed form: 51/2
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 21/84+90/18 21/42+90/36 63/42+90/18 21/42+90/54