Add 7/90 and 28/21
1st number: 7/90, 2nd number: 1 7/21
7/90 + 28/21 is 127/90.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 90 and 21 is 630
Next, find the equivalent fraction of both fractional numbers with denominator 630 - For the 1st fraction, since 90 × 7 = 630,
7/90 = 7 × 7/90 × 7 = 49/630 - Likewise, for the 2nd fraction, since 21 × 30 = 630,
28/21 = 28 × 30/21 × 30 = 840/630 - Add the two like fractions:
49/630 + 840/630 = 49 + 840/630 = 889/630 - 889/630 simplified gives 127/90
- So, 7/90 + 28/21 = 127/90
In mixed form: 137/90
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 14/90+28/21 7/90+56/21 7/90+28/42 21/90+28/21 7/90+84/21 7/90+28/63 35/90+28/21 49/90+28/21