A box model represents a division equation as the area of a rectangle divided by the number of rows or columns. When given the number of rows, the resulting number of columns can be determined using the equal parts method by partitioning the total area of the grid into columns with the same number of rows. Box models are the opposite of area models, which are used for multiplication equations.

To use a box model for division, follow these steps:

- Draw a rectangle.
- Divide the rectangle into rows equal to the divisor in the equation.
- Further divide the rectangle into columns so that the total number of cells is equal to the number being divided (dividend).
- The number of cells in each row is the quotient.

For example, let's consider the division equation 6 ÷ 2 = 3:

- Divide the rectangle into 2 rows.
- Divide the rectangle into columns so that the resulting number of cells is 6.
- Count the number of cells in each row, which is 3.