Extending Number Sense: Place Value CHAPTER 8 Tina Rye Sloan To accompany Helping Children Learn Math9e, Reys et al. ©2009 John Wiley & Sons

Extending Number Sense:

Place Value

CHAPTER 8

Tina Rye SloanTo accompany Helping Children Learn Math9e, Reys et al.

©2009 John Wiley & Sons

Focus Questions

• What are some instructional models that can help develop children’s understanding of our number system?

• Why is composing and decomposing numbers important in developing place value?

• How can calculators help children develop place value concepts?

• How do number names differ from country to country?

Reys/ Lindquist/ Lamdin/ Smith, Helping Children Learn Math,9th Edition, © 2009

Understand numbers, ways of representing numbers, relationships among numbers, and number systems

Grades Pre-K-2• Use multiple models to develop initial understandings of place value

and the base-ten number system.

• Develop a sense of whole numbers and represent and use them in flexible ways, including relating, composing, and decomposing numbers.

• Connect number words and numerals to the quantities they represent, using various physical models and representations.

(NCTM, 2000). Principles and Standards for School Mathematics.


Grades 3-5•Understand the place-value structure of the base-ten

number system and be able to represent and compare whole numbers and decimals.

•Recognize equivalent representations for the same number and generate them by decomposing and composing numbers.

(NCTM, 2000). Principles and Standards for School Mathematics.


Understand numbers, ways of representing numbers, relationships among numbers, and number systems

Ungrouped and Pregrouped Materials


Figure 8-4 Ungrouped and pregrouped models for developing place value

Place Value Models (for base ten)

1. Proportional-The material for 10 is ten times the size of 1; 100 is ten times the size of 10. Ex. base ten blocks, bean sticks, bundled sticks

Tens Ones 2 3


Place Value Models (for base ten)

•Non-proportional-The material does not maintain any size relationships. Ex. money, abacus, color tiles or chips

Tens Ones


Proportional and Nonproportional Models


Place Value Models

Concrete Physical Models =>

Semi-concreteOrganizational Models Tens | Ones Symbolic 2 | 5 Representational

Models

25


Beginning Place Value (Early Childhood)

•A Place to Start: Common Errors


Early Childhood Place Value

The notion of representing a quantity with the least number of pieces for a particular model is critical in place value. Establishing its importance at an early stage can eliminate some later errors such as the one indicated.


Ten-Frame Model


Extending Place Value

Using the same digits to represent different numbers helps children appreciate the importance of representing the place values accurately.


Extending Place Value

The front-end approach can be naturally extended and applied to larger numbers:


Extending Place Value: Counting and Patterns

•Calculators are useful in counting and pattern recognition.


Extending Place Value: Regrouping and Renaming


Figure 8-14 Nonproportional model illustrating relation between regrouping and place value

Reading and Writing Numbers

•Reading and writing numbers are symbolic activities and should follow much modeling and talking about numbers.


Reading and Writing Numbers

Although it seems logical to write number words as they sound, this procedure can lead to difficulty. If this were done, sixty one would be incorrectly written as 601 and one hundred twenty three as 100203. If a child made this mistake, the teacher could

use the place value mat as a model to demonstrate:


Rounding

• The precision of the rounded numbers reflects the problem context. For example, a meter stick could serve as a number line. Consider this train of rods, with 7 decimeter rods and 4 centimeter rods.

• Is the train closer to 7 or 8 decimeters? [7 decimeters]Is it closer to 0 or 1 meter? [1 meter]


Rounding (cont’d)

A roller coaster model could be used to develop rounding skills.


Cultural Connections

Can you write the number 751 using the Chinese numeration system?


Interviewer, "Circle in your drawing

what the six means. Circle what this part

(points to one) means.“

Abbie: Fifth Month of Second Grade


Student Interviews

Interviewer, "I'm going to say a number and I want you to write it... thirteen...sixty-seven...one hundred twenty...three hundred twenty-four... four hundred eight...three thousand, five hundred twenty-three.”


Student Interviews (cont’d)

Abbie: Fifth Month of Second Grade

Interviewer,

"Circle in your drawing what the 4 means. Circle what this part (points to one)

means.“

Clay: Fifth Month of Fourth Grade



Interviewer, "I'm going to say a number and I want you to write it...fifty-six...three hundred forty-eight...four hundred five... two thousand, seven hundred thirty one...thirty-five thousand, forty-eight.” Clay: Fifth Month of Fourth Grade



Interviewer, "Circle in your drawing what the 4

means. Circle in your drawing what this part (points to one) means."

Elsa: Fifth Month of Fourth Grade



Interviewer, "I'm going to say a number and I want

you to write it... three hundred forty-eight...four

hundred five... two thousand, seven hundred

thirty-one...thirty-five thousand, forty-eight.“

Elsa: Fifth Month of Fourth Grade



Documents

Extending Number Sense: Place Value CHAPTER 8 Tina Rye Sloan To accompany Helping Children Learn Math9e, Reys et al. ©2009 John Wiley & Sons