A rectangular piece of cardboard measures 10-inches by 20-inches.  How many 4-inch squares can be cut from the large piece?

 

 

Here we want to see if the student understands the difference between a 4-inch square and 4 square inches.  A 4-inch square has sides that each measure 4 inches and has an area of 16 square inches.  By drawing a diagram such as this we can see that there are 10 4-inch squares and the left over parts cannot be cut into 4-inch squares without putting some pieces together.