Add 12/90 and 3/21
12/90 + 3/21 is 29/105.
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,
12/90 = 12 × 7/90 × 7 = 84/630 - Likewise, for the 2nd fraction, since 21 × 30 = 630,
3/21 = 3 × 30/21 × 30 = 90/630 - Add the two like fractions:
84/630 + 90/630 = 84 + 90/630 = 174/630 - 174/630 simplified gives 29/105
- So, 12/90 + 3/21 = 29/105
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 24/90+3/21 12/90+6/21 12/90+3/42 36/90+3/21 12/90+9/21 12/90+3/63 60/90+3/21 12/90+15/21 84/90+3/21