Add 21/4 and 42/90
1st number: 5 1/4, 2nd number: 42/90
21/4 + 42/90 is 343/60.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 4 and 90 is 180
Next, find the equivalent fraction of both fractional numbers with denominator 180 - For the 1st fraction, since 4 × 45 = 180,
21/4 = 21 × 45/4 × 45 = 945/180 - Likewise, for the 2nd fraction, since 90 × 2 = 180,
42/90 = 42 × 2/90 × 2 = 84/180 - Add the two like fractions:
945/180 + 84/180 = 945 + 84/180 = 1029/180 - 1029/180 simplified gives 343/60
- So, 21/4 + 42/90 = 343/60
In mixed form: 543/60
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/4+42/90 21/4+84/90 21/8+42/90 63/4+42/90 21/12+42/90 21/20+42/90 21/28+42/90