How to Build a Self Propelled Toy Car

Fold the art foam in half width-wise. Draw a rounded rectangle covering most of the half sheet and incorporating the fold.

Draw a 2-inch half circle at the fold, 1/3 inch from the fold edge.

Draw 1/2-inch squares near the bottom rounded rectangle corners.

Cut out the rounded rectangle, the half circle and the squares with the mat knife while the art foam is folded.

Pinch together the inside edges of the rectangle at the opposite end from the half circle and add a glue dot to secure it.

Draw two 2-inch diameter circles with the compass. Draw two 1 3/4-inch diameter circles with the compass.

Cut out the circles and paint them black with silver center circles for wheels.

Cut two sections of straw to measure 3 inches each. Thread them through the small squares on the bottom of the car for axles.

Glue the wheels to the ends of the straws, placing the smaller wheels at the front of the car.

Tape the balloon on the end of straw. Thread the straw under the body of the car, above the axels with the balloon at the front of the car.

Blow up the balloon through the straw, put the car on a flat surface and watch it take off.