Add 30/40 and 36/21
1st number: 30/40, 2nd number: 1 15/21
30/40 + 36/21 is 69/28.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 40 and 21 is 840
Next, find the equivalent fraction of both fractional numbers with denominator 840 - For the 1st fraction, since 40 × 21 = 840,
30/40 = 30 × 21/40 × 21 = 630/840 - Likewise, for the 2nd fraction, since 21 × 40 = 840,
36/21 = 36 × 40/21 × 40 = 1440/840 - Add the two like fractions:
630/840 + 1440/840 = 630 + 1440/840 = 2070/840 - 2070/840 simplified gives 69/28
- So, 30/40 + 36/21 = 69/28
In mixed form: 213/28
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 60/40+36/21 30/40+72/21 30/80+36/21 30/40+36/42 90/40+36/21 30/40+36/63