Add 21/40 and 12/28
21/40 + 12/28 is 267/280.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 40 and 28 is 280
Next, find the equivalent fraction of both fractional numbers with denominator 280 - For the 1st fraction, since 40 × 7 = 280,
21/40 = 21 × 7/40 × 7 = 147/280 - Likewise, for the 2nd fraction, since 28 × 10 = 280,
12/28 = 12 × 10/28 × 10 = 120/280 - Add the two like fractions:
147/280 + 120/280 = 147 + 120/280 = 267/280 - So, 21/40 + 12/28 = 267/280
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/40+12/28 21/40+24/28 21/80+12/28 21/40+12/56 63/40+12/28 21/40+36/28 21/40+12/84 21/40+60/28 21/40+84/28