Add 21/30 and 81/8
1st number: 21/30, 2nd number: 10 1/8
21/30 + 81/8 is 433/40.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 30 and 8 is 120
Next, find the equivalent fraction of both fractional numbers with denominator 120 - For the 1st fraction, since 30 × 4 = 120,
21/30 = 21 × 4/30 × 4 = 84/120 - Likewise, for the 2nd fraction, since 8 × 15 = 120,
81/8 = 81 × 15/8 × 15 = 1215/120 - Add the two like fractions:
84/120 + 1215/120 = 84 + 1215/120 = 1299/120 - 1299/120 simplified gives 433/40
- So, 21/30 + 81/8 = 433/40
In mixed form: 1033/40
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/30+81/8 21/60+81/8 21/30+81/16 63/30+81/8 21/90+81/8 21/30+81/24 21/30+81/40 21/30+81/56