Add 28/54 and 5/21
28/54 + 5/21 is 143/189.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 54 and 21 is 378
Next, find the equivalent fraction of both fractional numbers with denominator 378 - For the 1st fraction, since 54 × 7 = 378,
28/54 = 28 × 7/54 × 7 = 196/378 - Likewise, for the 2nd fraction, since 21 × 18 = 378,
5/21 = 5 × 18/21 × 18 = 90/378 - Add the two like fractions:
196/378 + 90/378 = 196 + 90/378 = 286/378 - 286/378 simplified gives 143/189
- So, 28/54 + 5/21 = 143/189
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 56/54+5/21 28/54+10/21 28/54+5/42 84/54+5/21 28/54+15/21 28/54+5/63 28/54+25/21 28/54+35/21