i use the basics to teach other concepts such as coloured circles with seasonal pictures on them. I might name a colour and the child chooses the red circle and then tells what is on it. So we are reviewing colours as we name animals. Same works for shapes. I include the ones we know and add more as the group warrants. If I have older kids I just make a point to ask the younger kids a question that has them choosing a circle or square and ask the older kids a question that has them naming a pentagon or octagon.