Add 21/30 and 9/72
21/30 + 9/72 is 33/40.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 30 and 72 is 360
Next, find the equivalent fraction of both fractional numbers with denominator 360 - For the 1st fraction, since 30 × 12 = 360,
21/30 = 21 × 12/30 × 12 = 252/360 - Likewise, for the 2nd fraction, since 72 × 5 = 360,
9/72 = 9 × 5/72 × 5 = 45/360 - Add the two like fractions:
252/360 + 45/360 = 252 + 45/360 = 297/360 - 297/360 simplified gives 33/40
- So, 21/30 + 9/72 = 33/40
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/30+9/72 21/30+18/72 21/60+9/72 63/30+9/72 21/30+27/72 21/90+9/72 21/30+45/72 21/30+63/72