home elementary second third fourth comparisons math art book

# Place Value Activity

## Materials

• Place value sheets, pages 113-114 (1 set per student)

• Crayons (4 colors per student)

• Scissors (1 per student)

• Glue sticks (1 per student)

• 12" x 18" construction paper (1 sheet per student)

• Dark markers (1 per student)

• The completed project prepared by the teacher before the lesson

## Introduction

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.

Here, the value of each base 10-block has been shifted down two places for the sake of representing smaller numbers. But reusing blocks in this way is problematic, since it fails to truly represent how decimal place values differ from other place values. Isn’t it safer to just tell students that we can’t represent decimals using base-10 blocks because none exist that are small enough for the purpose?