Add 12/90 and 54/21
1st number: 12/90, 2nd number: 2 12/21
12/90 + 54/21 is 284/105.
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,
54/21 = 54 × 30/21 × 30 = 1620/630 - Add the two like fractions:
84/630 + 1620/630 = 84 + 1620/630 = 1704/630 - 1704/630 simplified gives 284/105
- So, 12/90 + 54/21 = 284/105
In mixed form: 274/105
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 24/90+54/21 12/90+54/42 36/90+54/21 12/90+54/63 60/90+54/21 84/90+54/21