Explanation:
The smallest number of packs you can have is.....
So we need to find the least common multiple of 8 and 10.
The LCM of 8 and 10 is 40.
Let's prove it:
40 / 8 = 5
40 / 10 = 4
So it is the LCM!
We also now know, that you will need 5 packs of pencils, and 4 packs of erasers to have the same amount of each!