- Identify the shape and formula: The problem asks for the volume of a box. A box is a rectangular prism. The volume of a rectangular prism is given by the formula $V = lwh$, where $l$ is the length, $w$ is the width, and $h$ is the height.
- Determine the dimensions: The problem states that the original length of each side of the cardboard was 9 inches. Since it's a square piece of cardboard, the length and width of the base of the box are determined by how it's folded. However, the question implies a simple cube if no cuts or folds are specified. If the cardboard itself forms the box without any cuts or modifications, and the original length of each side was 9 inches, it suggests a cube with side length 9 inches.
3. Calculate the volume: Using the formula for the volume of a cube, which is $V = s^3$ (where $s$ is the side length), we substitute the given side length:
$V = 9^3$
$V = 9 \times 9 \times 9$
$V = 81 \times 9$
$V = 729$
The volume is in cubic inches since the side length is in inches.