Students reflect on the physics of their favorite childhood activity and play with toys (balls, marbles, toy cars, ramps and anything else you have!) to construct their own understanding of force and motion. Then, students use the PhET simulations Balancing Act and Force and Motion to increase their knowledge of Newton's first and second laws. Students practice calculating the net force on an object. Then, they plan and carry out their own investigation to answer the question “How do mass and force affect an object’s motion?” Finally, students share what they learned in a written claim, evidence and reasoning.