Add 28/21 and 4/90
1st number: 1 7/21, 2nd number: 4/90
28/21 + 4/90 is 62/45.
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,
28/21 = 28 × 30/21 × 30 = 840/630 - Likewise, for the 2nd fraction, since 90 × 7 = 630,
4/90 = 4 × 7/90 × 7 = 28/630 - Add the two like fractions:
840/630 + 28/630 = 840 + 28/630 = 868/630 - 868/630 simplified gives 62/45
- So, 28/21 + 4/90 = 62/45
In mixed form: 117/45
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 56/21+4/90 28/21+8/90 28/42+4/90 84/21+4/90 28/21+12/90 28/63+4/90 28/21+20/90 28/21+28/90