Stacey needs to buy some cardboard to build a box 10 inches long, 9 inches wide, and 7 inches high. If she purchases 500 square inches of cardboard, how much will be left over?

Answer 1

To find the total surface area of the box, we need to calculate the surface area of each side and then add them all together.

The box has 6 sides:
1. Top and bottom: 10 inches long by 9 inches wide = 90 square inches each (2 sides total)
2. Front and back: 10 inches long by 7 inches high = 70 square inches each (2 sides total)
3. Sides: 9 inches wide by 7 inches high = 63 square inches each (2 sides total)

Total surface area of the box: (90 + 90) + (70 + 70) + (63 + 63) = 446 square inches

If Stacey purchases 500 square inches of cardboard and the total surface area of the box is 446 square inches, then there will be 500 - 446 = 54 square inches left over.