Add 12/72 and 21/40
12/72 + 21/40 is 83/120.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 72 and 40 is 360
Next, find the equivalent fraction of both fractional numbers with denominator 360 - For the 1st fraction, since 72 × 5 = 360,
12/72 = 12 × 5/72 × 5 = 60/360 - Likewise, for the 2nd fraction, since 40 × 9 = 360,
21/40 = 21 × 9/40 × 9 = 189/360 - Add the two like fractions:
60/360 + 189/360 = 60 + 189/360 = 249/360 - 249/360 simplified gives 83/120
- So, 12/72 + 21/40 = 83/120
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 24/72+21/40 12/72+42/40 12/72+21/80 36/72+21/40 12/72+63/40 60/72+21/40 84/72+21/40