Alexander built a toy box in the shape of a rectangular prism with an open top. The diagram below shows the toy box and a net of the toy box NET OF TOY BOX dimensions:

To find the surface area of the toy box, we need to calculate the area of each of the six faces and then add them up.

1. Top and bottom faces:
These faces are rectangles with dimensions 14 cm by 10 cm.
So, the area of each of these faces is:
14 cm * 10 cm = 140 cm^2
Since there are two of these faces, the total area for both the top and bottom faces is:
2 * 140 cm^2 = 280 cm^2

2. Front and back faces:
These faces are rectangles with dimensions 14 cm by 9 cm.
So, the area of each of these faces is:
14 cm * 9 cm = 126 cm^2
Since there are two of these faces, the total area for both the front and back faces is:
2 * 126 cm^2 = 252 cm^2

3. Side faces:
These faces are rectangles with dimensions 9 cm by 10 cm.
So, the area of each of these faces is:
9 cm * 10 cm = 90 cm^2
Since there are two of these faces, the total area for both side faces is:
2 * 90 cm^2 = 180 cm^2

Adding up the areas of all six faces, we get:
280 cm^2 + 252 cm^2 + 180 cm^2 = 712 cm^2

Therefore, the surface area of the toy box is 712 square centimeters.