Surface area. Figuring out the answer

Question

if Sam is making a cardboard box that is 18 inches long, 12 inches wide, and 19 inches tall, he needs to measure the box by 1 inch squares. He wants to find out how many squares it would need to make the box with no overlapping in the construction

Answer 1

1572 - overlapping squares in the box corners

18x12x19= 4104

in feet = 1.5x1x19/12 = 3/2 x 19/12 = 19/8 = 2 3/8 ft^3= (19/8)(12^3) = 4104 in^3

but you want "squares" for the 6 sides of the box, not cubes for the volume

that's 2(12x19) +2(12x18) +2(19x18) minus overlapping squares on the 8 corners

= 456+432+684= 1572- 8 = 1564 squares

Answer 2

So there are 6 sides to the box.

2 sides of size 12in. by 18in. = 12in x 18in = 216 square inches = 216 inch squares

2 sides of 12in by 19in = 12in x 19in = 228 square inches = 228 inch squares

2 sides of 18in by 19in = 18in x 19in = 342 square inches = 342 inch squares

So the total is 2 * 216 + 2 * 228 + 2 * 342 = 432 + 456 + 684 = 888 + 684 = 1572 inch squares