Add 3/21 and 90/81
1st number: 3/21, 2nd number: 1 9/81
3/21 + 90/81 is 79/63.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 81 is 567
Next, find the equivalent fraction of both fractional numbers with denominator 567 - For the 1st fraction, since 21 × 27 = 567,
3/21 = 3 × 27/21 × 27 = 81/567 - Likewise, for the 2nd fraction, since 81 × 7 = 567,
90/81 = 90 × 7/81 × 7 = 630/567 - Add the two like fractions:
81/567 + 630/567 = 81 + 630/567 = 711/567 - 711/567 simplified gives 79/63
- So, 3/21 + 90/81 = 79/63
In mixed form: 116/63
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 6/21+90/81 3/42+90/81 9/21+90/81 3/63+90/81 15/21+90/81