Penny has been hired to paint 5 bulletin boards at her school. To calculate the amount of surface she needs to paint, she multiplies the length of one side of one bulletin board by itself and then multiplies the product by 5. Based on Penny's calculations, what do we know about the bulletin board and her calculations?

These bulletin boards must be square.

Based on Penny's calculations, we know that the bulletin board has sides of equal length, as she multiplies the length of one side by itself. This implies that the bulletin boards are square-shaped.

To calculate the amount of surface she needs to paint, Penny multiplies the length of one side of the bulletin board by itself to find the area of one bulletin board. Then, she multiplies this product by 5 to account for the five bulletin boards she needs to paint.

In other words, if we let "x" represent the length of one side of the bulletin board, Penny's calculations can be expressed as:

Area of one bulletin board = x * x = x^2
Total area to paint = x^2 * 5

This means that she needs to paint a total area of 5 times the area of one bulletin board, as each bulletin board has the same dimensions.