A single layer of each wall requires 5 rows * 20 bricks per row = <<5*20=100>>100 bricks.

As each wall has a thickness of 2 bricks, he will need 100 bricks * 2 = <<100*2=200>>200 bricks per wall.

If the complete fence contains four walls, he will require a total of 200*4=<<200*4=800>>800 bricks.

# Answer

800
<|im_start|>system
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<|im_start|>user
Cooper is building a brick fence around all four sides of his property.  Each of the four walls of his fence is 20 bricks long, 5 bricks high, and 2 bricks deep.  How many bricks does Cooper need to complete his fence?
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
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user
800
Cooper is building a brick fence around all four sides of his property.  Each of the four walls of his fence is 20 bricks long, 5 bricks high, and 2 bricks deep.  How many bricks does Cooper need to complete his fence?
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