Add 30/90 and 18/42
30/90 + 18/42 is 16/21.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 90 and 42 is 630
Next, find the equivalent fraction of both fractional numbers with denominator 630 - For the 1st fraction, since 90 × 7 = 630,
30/90 = 30 × 7/90 × 7 = 210/630 - Likewise, for the 2nd fraction, since 42 × 15 = 630,
18/42 = 18 × 15/42 × 15 = 270/630 - Add the two like fractions:
210/630 + 270/630 = 210 + 270/630 = 480/630 - 480/630 simplified gives 16/21
- So, 30/90 + 18/42 = 16/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 60/90+18/42 30/90+36/42 30/90+18/84 30/90+54/42 30/90+90/42