How does increasing the number of charges affect the electric field strength for a given distance?

You'd have no problem with that question if I asked you "How does increasing

the amount of charge affect the electric field strength for a given distance?

Obviously the electric field strength at some distance would increase in direct

proportion to the amount of charge (as long as the charge is all the same sign).

Well, it wasn't until about 100 years ago that anybody knew that there was

such a thing as the "number of charges". It was thought that charge is

continuous, just like the way we think of water, and that there was no such

thing as the "smallest piece".

If the distance from all charges is the same, no matter whether they're all

electrons or balloons, then the field depends only on the total amount of charge.