Add 4/21 and 84/90
4/21 + 84/90 is 118/105.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 90 is 630
Next, find the equivalent fraction of both fractional numbers with denominator 630 - For the 1st fraction, since 21 × 30 = 630,
4/21 = 4 × 30/21 × 30 = 120/630 - Likewise, for the 2nd fraction, since 90 × 7 = 630,
84/90 = 84 × 7/90 × 7 = 588/630 - Add the two like fractions:
120/630 + 588/630 = 120 + 588/630 = 708/630 - 708/630 simplified gives 118/105
- So, 4/21 + 84/90 = 118/105
In mixed form: 113/105
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 8/21+84/90 4/42+84/90 12/21+84/90 4/63+84/90 20/21+84/90 28/21+84/90