Add 45/90 and 40/21
1st number: 45/90, 2nd number: 1 19/21
45/90 + 40/21 is 101/42.
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,
45/90 = 45 × 7/90 × 7 = 315/630 - Likewise, for the 2nd fraction, since 21 × 30 = 630,
40/21 = 40 × 30/21 × 30 = 1200/630 - Add the two like fractions:
315/630 + 1200/630 = 315 + 1200/630 = 1515/630 - 1515/630 simplified gives 101/42
- So, 45/90 + 40/21 = 101/42
In mixed form: 217/42
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 45/90+80/21 45/90+40/42 45/90+40/63