Add 21/30 and 18/45
21/30 + 18/45 is 11/10.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 30 and 45 is 90
Next, find the equivalent fraction of both fractional numbers with denominator 90 - For the 1st fraction, since 30 × 3 = 90,
21/30 = 21 × 3/30 × 3 = 63/90 - Likewise, for the 2nd fraction, since 45 × 2 = 90,
18/45 = 18 × 2/45 × 2 = 36/90 - Add the two like fractions:
63/90 + 36/90 = 63 + 36/90 = 99/90 - 99/90 simplified gives 11/10
- So, 21/30 + 18/45 = 11/10
In mixed form: 11/10
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/30+18/45 21/30+36/45 21/60+18/45 21/30+18/90 63/30+18/45 21/30+54/45 21/90+18/45 21/30+90/45