The entire volume of ice cream in the cylinder must equal the entire volume of all the ice cream scoops.

Shape allows us to use a volume formula.

The volume of a cylinder is (circle area)(height) =

The volume of our cylinder is

The scoops are spherical.

the volume of a sphere is

The volume of one scoop is

Dividing the cylinder volume by the sphere volume gives the number of scoops, since all those scoops of ice cream makes up the full amount of ice cream in the container.