topic badge
Australia
Year 4

1.04 Partition 5 digit numbers

Lesson

Are you ready?

Can you partition numbers up to the thousands (4 digits)?

Examples

Example 1

We have written a number in the number expander.

A number expander with 3 thousands, 9 hundreds, 8 tens, and 2 units.
a

What is the value of the tens?

Worked Solution
Create a strategy

Use the given number expander. Add 0 as a placeholder.

Apply the idea

We can see from the number expander that we have 8 tens which is equal to 80.

b

What is the value of the hundreds?

Worked Solution
Create a strategy

Use the given number expander. Add 0 as a placeholder.

Apply the idea

We can see from the number expander that we have 9 hundreds which is equal to 900.

Idea summary

Numbers can be described using any place value such as thousands, hundreds, tens and units.

Expanded notation of 5 digit numbers

Let's see how to break up a 5 digit number, and then put it back together. We'll start with a 4 digit number to warm up.

Loading video...

Exploration

Enter a five digit number into the applet and drag the number tiles around to see what amount each digit represents.

Loading interactive...

Any five digit number can be expanded by their ten thousands, thousands, hundreds, tens, and units value.

Examples

Example 2

Fill in the number expander for 60\,908.

a
60\,908=\text{ten thousands}\text{thousands}\text{hundreds}0\text{tens}8\text{units}
Worked Solution
Create a strategy

Put the given number in a place value table.

Apply the idea
Ten thousandsThousandsHundredsTensUnits
60908

So, the complete number expander is:

60\,908=6\text{ten thousands}0\text{thousands}9\text{hundreds}0\text{tens}8\text{units}
b

Write 60\,908 as a number sentence.

⬚+⬚+⬚

Worked Solution
Create a strategy

Use the number expander from part (a).

Apply the idea

6 ten thousands is 60\,000, 9 hundreds is 900, and 8 units is 8.

60\,908=60\,000+900+8

Example 3

Write the following as a single number: 10\,000+7000+90.

Worked Solution
Create a strategy

Put each first digit in a place value table. For the values not given, use 0 as placeholder.

Apply the idea
Ten thousandsThousandsHundredsTensUnits
17090

The place value table shows how the values add together.

10\,000+7000+90 = 17\,090

Idea summary

Except for the far left digit of our number, every place must have a number in it. If we don't have any of a place, we must put a zero in that place. The number twenty eight thousand and forty nine has no hundreds, so we would write it like this 28\,049.

Outcomes

ACMNA072

Recognise, represent and order numbers to at least tens of thousands

ACMNA073

Apply place value to partition, rearrange and regroup numbers to at least tens of thousands to assist calculations and solve problems

ACMNA076

Develop efficient mental and written strategies and use appropriate digital technologies for multiplication and for division where there is no remainder

What is Mathspace

About Mathspace