The instruction manual contains a lot of advanced science. Although some of the directions may be a bit hard to follow, persevering through the instructions is well worth it. The products are spectacular; they are sturdy and really roll. The solar panel swivels to catch the best rays. Children can time how fast the vehicles move in forward and reverse. They can add loads to their solar pickup trucks and see how much weight they carry. The vehicles climb hills, and children can measure the slopes. All of these are hands-on ways of learning math and science. This is a versatile and satisfying kit with important lessons. In this era of dwindling resources, we really want to inspire budding solar engineers.