This paper plate sundial using straws, markers or crayons is an easy, fun, and effective way to help kids learn about time. Take the sundial outside at noon and let the kids mark the hours.
Some questions to ask the kids might be: Were the marks at regular intervals? Older kids might notice that a circle has 360 degrees and the day has 24 hours so if the hours are marked at regular intervals, they would be at every 15 degrees.
Will the sundial work tomorrow? How about three months from now?
Adapt the project to the appropriate age-level of your child and let them enjoy constructing their new "clock".