Add 4/84 and 21/80
4/84 + 21/80 is 521/1680.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 84 and 80 is 1680
Next, find the equivalent fraction of both fractional numbers with denominator 1680 - For the 1st fraction, since 84 × 20 = 1680,
4/84 = 4 × 20/84 × 20 = 80/1680 - Likewise, for the 2nd fraction, since 80 × 21 = 1680,
21/80 = 21 × 21/80 × 21 = 441/1680 - Add the two like fractions:
80/1680 + 441/1680 = 80 + 441/1680 = 521/1680 - So, 4/84 + 21/80 = 521/1680
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 8/84+21/80 4/84+42/80 12/84+21/80 4/84+63/80 20/84+21/80 28/84+21/80