Math is Elemental

The introduction of Decimals is a good time to show that the Ones column is the foundation of the numbering system. The Place Value chart is symmetrical around this column - not the Decimal Point. Too many students think the Decimal Point is the center. Too many PV charts imply the Decimal Point is the center. Emphasizing the Ones column helps address this common mistake. Note: The Ones column is not labeled as Whole Numbers to emphasize the symmetry of Place Value.

This handout is not intended to replace the valuable interactive exercise of rounding on an open number line. Once the rounding concept of the 'closest number' is understood, this summary can help with the mechanics.

This introduction to decimals leverages what students already know about place value and fractions to teach the first decimal place.