Add 90/10 and 81/21
1st number: 9 0/10, 2nd number: 3 18/21
90/10 + 81/21 is 90/7.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 10 and 21 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 10 × 21 = 210,
90/10 = 90 × 21/10 × 21 = 1890/210 - Likewise, for the 2nd fraction, since 21 × 10 = 210,
81/21 = 81 × 10/21 × 10 = 810/210 - Add the two like fractions:
1890/210 + 810/210 = 1890 + 810/210 = 2700/210 - 2700/210 simplified gives 90/7
- So, 90/10 + 81/21 = 90/7
In mixed form: 126/7
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 90/20+81/21 90/10+81/42 90/30+81/21 90/10+81/63 90/50+81/21 90/70+81/21