A cube gift box, edge length of 1.2 decimeters, how many square decimeters of wrapping paper to wrap this gift box at least? Detailed formula!

A cube gift box, edge length of 1.2 decimeters, how many square decimeters of wrapping paper to wrap this gift box at least? Detailed formula!

1.2 times 1.2 = 1.44 (square decimeter)
1.44 times 6 = 8.64 (square decimeter)

How many square centimeters of wrapping paper is needed to pack a cube gift box with 3 edges and a length of 8 cm?
Don't worry about the equation

Packaging: 3 * 8 * 8 * 6 = 1152 square centimeter
Stacked package: 1152-8 * 8 * 4 = 896 square centimeters

How much wrapping paper does Huanhuan need to pack a cube gift box with 5 / 2 of its edge length?

The problem is the surface area
Because it's a cube, the surface area is six times the area of a surface
S = (5 / 2) * (5 / 2) * 6 = 75 / 2 square decimeter