Basic 4 · Mathematics · Counting, Representation and Cardinality
Numbers up to 100,000 and Place Value
In this topic you will read, write and model numbers up to 100,000, and find the place value of each digit.
By the end of these notes you should be able to:
- Read and write numbers up to 100,000 in figures and words
- Identify the place value and value of each digit
- Model numbers using graph sheets and place value charts
What you already know
- Numbers up to 10,000 (Basic 3)
Copy everything that has a blue line on its left into your notebook. The other parts are for reading.
- Strand
- Number
- Sub-strand
- Counting, Representation and Cardinality
- Indicator
- B4.1.1.1.1 – Model number quantities and place values for multi-digit numerals up to 100,000 using graph sheets and multi-base materials
Introduction
The population of a large town like Techiman is more than 100,000 people. To read and understand big numbers, we need to know place value up to ten thousands and hundred thousands.
1. The Place Value Chart
Each place is ten times the place on its right.
| Ten thousands | Thousands | Hundreds | Tens | Ones |
|---|---|---|---|---|
| 4 | 6 | 3 | 8 | 2 |
46,382 is read as "forty-six thousand, three hundred and eighty-two".
| Digit | Place | Value |
|---|---|---|
| 4 | ten thousands | 40,000 |
| 6 | thousands | 6,000 |
| 3 | hundreds | 300 |
| 8 | tens | 80 |
| 2 | ones | 2 |
2. Modelling with a Graph Sheet
On a graph sheet, one small square can stand for 1. A strip of 10 squares stands for 10. A block of 10 × 10 squares stands for 100.
To model 1,250 you could shade 12 blocks of 100, then 5 strips of 10.
3. Writing Numbers
Example 1
Write 70,509 in words.
- Split into thousands and the rest: 70 | 509
- 70 thousand
- 509 = five hundred and nine
Answer: Seventy thousand, five hundred and nine
Example 2
Write "thirty-two thousand and forty" in figures.
- Thirty-two thousand = 32,000
- Forty = 40
Answer: 32,000 + 40 = 32,040
Common mistake: In 32,040 the zeros hold the hundreds and ones places. Leaving them out gives 3,240, which is wrong.
Remember: 100,000 is "one hundred thousand". It has six digits.
New words
- place value
- The value of a digit because of its position.
- digit
- One of the symbols 0–9 used to write numbers.
- ten thousand
- Ten thousands; 10,000.
- hundred thousand
- 100,000.
- model
- To show a number using objects or drawings.
- expanded form
- A number written as the sum of its place values.
Summary
- Each place is ten times the place on its right.
- 46,382 = 40,000 + 6,000 + 300 + 80 + 2.
- Zeros hold empty places in a number.
- Graph sheets and charts help us model numbers.
Class activity: Graph Sheet Numbers
- Pick a number card between 100 and 2,000.
- Model it by shading a graph sheet using blocks of 100, strips of 10 and single squares.
- Write the number in figures, words and expanded form.
You need: Bundles of sticks, Place-value chart on manila card, Locally made digit cards
Exercises
Answer in your exercise book first, then check your answers.
1. What is the value of 7 in 57,214?
- A. 7,000
- B. 700
- C. 70
- D. 70,000
Show answer
Answer: 7,0007 is in the thousands place.2. Which number is "sixty thousand and six"?
- A. 60,006
- B. 60,060
- C. 66,000
- D. 6,006
Show answer
Answer: 60,006Sixty thousand plus six ones.3. Which is the expanded form of 23,405?
- A. 20,000 + 3,000 + 400 + 5
- B. 20,000 + 3,000 + 40 + 5
- C. 2,000 + 300 + 40 + 5
- D. 23,000 + 45
Show answer
Answer: 20,000 + 3,000 + 400 + 5There are no tens.4. 100,000 has six digits.
- A. True
- B. False
Show answer
Answer: True1, 0, 0, 0, 0, 0.5. In 81,936 the 9 is in the tens place.
- A. True
- B. False
Show answer
Answer: False9 is in the hundreds place.6. 50,000 + 4,000 + 200 + 7 = ______
Show answer
Answer: 54,207Add the place values.7. Write 90,815 in words.
Show answer
Answer: Ninety thousand, eight hundred and fifteen90 thousand and 815.8. How many hundreds are there in 4,500?
Show answer
Answer: 45 hundreds4,500 ÷ 100 = 45.
Homework
- Find the population of your district or town (ask an adult or check a book). Write it in words and in expanded form.