Add 90/10 and 72/21
1st number: 9 0/10, 2nd number: 3 9/21
90/10 + 72/21 is 87/7.
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,
72/21 = 72 × 10/21 × 10 = 720/210 - Add the two like fractions:
1890/210 + 720/210 = 1890 + 720/210 = 2610/210 - 2610/210 simplified gives 87/7
- So, 90/10 + 72/21 = 87/7
In mixed form: 123/7
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 90/20+72/21 90/10+72/42 90/30+72/21 90/10+72/63 90/50+72/21 90/70+72/21