Tim and Mary are building a special brick wall in the town playground. There will be 212 bricks in the bottom layer, 204 bricks in the second layer, 196 bricks in the third layer, and so on in the same
pattern. The wall will be 20 layers high. They want to know how many bricks will be in the top layer.

• Drag and drop a response into the first box that represents the explicit expression that can be used to find out how many bricks will be in the top layer.

• Drag and drop the number of bricks that will be in the top layer into the second box



a =
n

The number of bricks in the top layer is ____



Responses:

212+(n-1)(8)

212+ (n-1)(-8)

212+(8-1)(n)

212+(8-1)(-n)

60

72

352

364