Sometimes in sharing or measuring there is a need to use numbers between whole numbers.
Simple graphs can help to tell about observations.
Sometimes changing one thing causes changes in something else. In some situations, changing the same thing in the same way usually has the same result. Shapes, such as circles, squares, and triangles, can be used to describe many things that can be seen. Some events can be predicted well and some cannot. Sometimes people aren't sure what will happen because they don't know everything that might be causing an effect.