Add 21/40 and 84/45
1st number: 21/40, 2nd number: 1 39/45
21/40 + 84/45 is 287/120.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 40 and 45 is 360
Next, find the equivalent fraction of both fractional numbers with denominator 360 - For the 1st fraction, since 40 × 9 = 360,
21/40 = 21 × 9/40 × 9 = 189/360 - Likewise, for the 2nd fraction, since 45 × 8 = 360,
84/45 = 84 × 8/45 × 8 = 672/360 - Add the two like fractions:
189/360 + 672/360 = 189 + 672/360 = 861/360 - 861/360 simplified gives 287/120
- So, 21/40 + 84/45 = 287/120
In mixed form: 247/120
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/40+84/45 21/80+84/45 21/40+84/90 63/40+84/45