A: Each pencil box 12 yuan.
(2) 12- 12 = 1 (yuan)
A: The price of the eraser is 1 yuan.
(3) 12×4+5=53 (yuan)
A: The price of the schoolbag is 53 yuan.
(4) Question: How much is the pencil case more expensive than the eraser?
12-1=11(yuan)
A: The pencil case is more expensive than the eraser 1 1 yuan.