We have since buying our first box of bouncy balls purchased several more! They are fantastic birthday presents and hours of family fun. Our oldest loved making them, he is seven years old. Our five year old had help and made them with his dad. The kit does say on the box 8 plus. I think the kit can make several little balls if you don't make a huge balls only. He made a big and I think three small balls from one kit. They do loose their bounce in time, having said that the boys still wished to keep their balls as they are colourful and were such fun to make. My husband thought it taught them early science and about the properties of things. So educational too. The boys were able to follow the instructions, wait for a time when they had to for it to set and so on, again good practice of following steps and making sure each stage is done when it had to be done. One friend we gave it to as a birthday gift said it was the best present he had. Over thirty children were at his party and he rated this kit to be the best, the little boy was turning six. So I hope that helps...