Add 5/21 and 30/42
5/21 + 30/42 is 20/21.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 42 is 42
Next, find the equivalent fraction of both fractional numbers with denominator 42 - For the 1st fraction, since 21 × 2 = 42,
5/21 = 5 × 2/21 × 2 = 10/42 - Likewise, for the 2nd fraction, since 42 × 1 = 42,
30/42 = 30 × 1/42 × 1 = 30/42 - Add the two like fractions:
10/42 + 30/42 = 10 + 30/42 = 40/42 - 40/42 simplified gives 20/21
- So, 5/21 + 30/42 = 20/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 10/21+30/42 5/21+60/42 5/42+30/42 5/21+30/84 15/21+30/42 5/21+90/42 5/63+30/42 25/21+30/42 35/21+30/42