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?
446 square inches
54 square inches
426 square inches
406 square inches
To find out how much cardboard Stacey needs to build the box, calculate the surface area of each side of the box:
- Front and back sides: 10 inches x 7 inches = 70 square inches x 2 = 140 square inches
- Top and bottom sides: 10 inches x 9 inches = 90 square inches x 2 = 180 square inches
- Left and right sides: 9 inches x 7 inches = 63 square inches x 2 = 126 square inches
Total surface area needed: 140 square inches + 180 square inches + 126 square inches = 446 square inches
Since Stacey only has 500 square inches of cardboard, subtract the total surface area needed from the amount of cardboard she has to find out how much will be left over:
500 square inches - 446 square inches = 54 square inches
Therefore, Stacey will have 54 square inches of cardboard left over after building the box.
The answer is: 54 square inches.