To solve this, solve the area of the sheet of metal and also the area the sign. Then, divide the whole sheet metal by the area of the sign. Assuming from the given dimensions, the shape must be a rectangle. The area of a rectangle is length x width.
Area of Sheet metal = 6 x 12 = 72 ft2
Area of sign = 2 x 4 = 8 ft2
Number of signs = 72 ft2 ÷ 8 ft2
Number of signs = 9
He can make a total of 9 signs.