The top of this soda can and then we are going to multiply it by it's height and that'll give us a volume. this will tell us essentially how many square cm fit into this top and then if we know; if we multiply that by how many cm we go down, then that will give us the number of cubic centimeters in this cylinder, or soda can so how do we figure out this area up here well the area on top this is just finding the area of a circle you could imagine drawing it like this if we were just to look at it straight on that's a circle with a radius of 4 cm. the area of a circle with an area of 4 cm area is equal to pie r squared. so it's going to be pie times the radius squared times four cm squared which is equal to 4 squared is 16 times pie and our units now are going to be cm squared or another way to think of these is square cm so that's the area the volume is going to be this area times the height so the volume is going to be equal to 16 pie cm squared times the height times 8 cm times 8 cm and so when you do multiplication you could use the associative property you could kind of rearrange these things it doesn't matter what order you do it. it is all multiplication so this is the same thing as 16 times 8