Add 21/40 and 48/70
21/40 + 48/70 is 339/280.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 40 and 70 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 70 × 4 = 280,
48/70 = 48 × 4/70 × 4 = 192/280 - Add the two like fractions:
147/280 + 192/280 = 147 + 192/280 = 339/280 - So, 21/40 + 48/70 = 339/280
In mixed form: 159/280
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/40+48/70 21/40+96/70 21/80+48/70 63/40+48/70