Make a cardboard ramp for your child's finger skateboard or model cars. A cardboard ramp can be constructed in minutes in any size you desire. Corrugated cardboard allows you to make a sturdy ramp with only two seams, which will hold up to rough play. Glue sandpaper to the surface to provide a perfect gymnasium for tumbling elf toys. This ramp design is a model-inclined plane, one of the simple machines used to study the principles of elementary physics.

Draw a rectangle on a piece of corrugated cardboard. This rectangle will be the top of your ramp. A good size for this rectangle would be 5 inches by 9 inches.

Use a protractor to draw a line at a 30-degree angle from the long side of the rectangle starting at the corner. Draw a matching line on the other side of the rectangle. Draw a line at a 60-degree angle from the long side at the other two corners.

Extend the two lines until they connect, making a right triangle on each side of the rectangle. These are the sides of the ramp.

Measure the shortest side of one of the triangles. Extend the long sides of the rectangle by this amount on the end nearest to the short sides of the triangle. Draw a line connecting the endpoints of these new lines. This will form another rectangle.

Cut out this shape. Score the three lines on the shape with a box cutter. Cut through only the top layer of the cardboard.

Fold the cardboard down along these lines forming a ramp shape. Tape the back edges together.

#### Tip

Tape the back sides together on the inside if you want to decorate the whole surface of the ramp with markers. Glue sandpaper to the surface of the ramp if you wish to increase the friction of the surface. This helps if you will be using the ramp for tumbling toys.