Clock charts

 

Clock chart

Clock charts can build on prior, or currently developing, knowledge of clocks.  Clock charts provide an excellent mathematical framework for strengthening the concept of rational numbers (fractions) and the use of degrees for angular measurements.  The factors of sixty are one, two, two, three, and five.  The rational numbers, 1/2, 1/3, 1/4, 1/5, 1/6, 1/8 (yes, one knows exactly where to put it), 1/10, 1/12, 1/15, 1/20, 1/30, 1/60, and 1/120, are easy to identify and place on the chart.  Addition and subtraction of rational numbers can easily be checked visually with clock charts.


The history of pie charts is not fully know though some research has been done.