This is the standards chapter in the Principles and Standards for School Mathematics of the National Council of Teachers of Mathematics. Select Number and Operations from the left column for across-the-grades standards. For specific grade level standards select Pre-K - 2, 3 - 5, or 6 - 8, from the top row. (
http://standards.nctm.org/document/chapter3/index.htm
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This site contains the history of several ancient numeration systems. Select the Mayan, Babylonian, or Egyptian systems. (
http://www-groups.dcs.st-and.ac.uk/~history/Indexes/HistoryTopics.html
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To learn more about the book this website supports, please visit its Information Center.