Add 90/8 and 42/21
1st number: 11 2/8, 2nd number: 2 0/21
90/8 + 42/21 is 53/4.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 8 and 21 is 168
Next, find the equivalent fraction of both fractional numbers with denominator 168 - For the 1st fraction, since 8 × 21 = 168,
90/8 = 90 × 21/8 × 21 = 1890/168 - Likewise, for the 2nd fraction, since 21 × 8 = 168,
42/21 = 42 × 8/21 × 8 = 336/168 - Add the two like fractions:
1890/168 + 336/168 = 1890 + 336/168 = 2226/168 - 2226/168 simplified gives 53/4
- So, 90/8 + 42/21 = 53/4
In mixed form: 131/4
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 90/8+84/21 90/16+42/21 90/24+42/21 90/8+42/63 90/40+42/21 90/56+42/21