Add 40/90 and 45/21
1st number: 40/90, 2nd number: 2 3/21
40/90 + 45/21 is 163/63.
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,
40/90 = 40 × 7/90 × 7 = 280/630 - Likewise, for the 2nd fraction, since 21 × 30 = 630,
45/21 = 45 × 30/21 × 30 = 1350/630 - Add the two like fractions:
280/630 + 1350/630 = 280 + 1350/630 = 1630/630 - 1630/630 simplified gives 163/63
- So, 40/90 + 45/21 = 163/63
In mixed form: 237/63
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 80/90+45/21 40/90+90/21 40/90+45/42 40/90+45/63