Hi!
So we need to know how many times 6 goes into 21.
6, 12, 18, 24
6 doesn't go into 21 evenly, so Johnny will have to pick between buying 18 pencils, or 24 pencils.
If Johnny buys 3 packages, 3 students won't have any pencils. Which means Johnny has to buy 4 packages.
Hope this helps! :)
-Peredhel
