Place Value

This lesson helps students memorize place values. Furthermore, and perhaps more importantly, it lays the groundwork for decimal instruction, which is one of the most difficult topics to teach in elementary mathematics. Why are decimals so difficult?

• They complicate fraction instruction by placing importance on a limited number of denominators (tenths, hundredths, thousandths, etc).
• Students easily confuse them with negative numbers, since both topics introduce students to a set of numbers they never knew existed, namely numbers less than 1.
• Nine thousandths is less than one tenth? Why is that?
• There is no "oneths" place.
• Unlike other place values, decimal place values are not separated into groups of three by commas

In many classrooms, decimal place value is taught using base-10 blocks that look literally identical to the base-10 blocks used to teach “regular” place value.