# 1.10 Partition 3 digit numbers

Lesson

## Ideas

So far, we have seen how to  read, write and use place-value  blocks to make four-digit numbers.

### Examples

#### Example 1

What number is represented by these blocks?

Worked Solution
Create a strategy

Complete a place value table when counting the blocks.

Apply the idea

Each kind of block represents a different place value.

Here is the completed place value table:

The number is 345.

Idea summary

We can use a place value table to count the number of blocks.

## Numbers to 1000

This video looks at how we can break up numbers with place value, and how we can use that to solve problems.

### Exploration

Enter a three digit number into the applet and drag the place value cards around to see what amount each digit represents.

The place value cards can be used to write the expanded form of the numbers.

### Examples

#### Example 2

Complete the boxes with the missing numbers to write 728 in expanded form.

728=⬚+20+⬚

Worked Solution
Create a strategy

Write the first number in a place value table.

Apply the idea

Here is the complete table:

We have 7 hundreds which equals 700.

We have 2 tens which equals 20.

We have 8 units which equals 8.

Idea summary

We can use a place value table to write a number in expanded form.

## Number expander

This video shows you how to use a number expander to write a number in different ways. Why not try making a number expander with paper?

### Examples

#### Example 3

We have written the number 305 in a number expander.

Complete the boxes below to make the sentences correct.

a

This number is made up of hundreds and 5 units.

Worked Solution
Create a strategy

We can use the number expander to find what the number is in the hundreds place.

Apply the idea

In the number expander, 3 is in the hundreds place, 0 is in the tens place, and 5 is in the units place.

This number is made up of 3 hundreds and 5 units.

b

We can also write the number using only tens and units.

Writing it this way, 305 is made up of tens and 5 units.

Worked Solution
Create a strategy

Use the folded number expander:

Apply the idea

From the folded number expander we have 30 tens and 5 units.

Writing it this way, 305 is made up of 30 tens and 5 units.

Idea summary

Even though we might think of 500 as 5 hundreds, we can also think of it as 50 tens, or 500 units.

### Outcomes

#### MA2-4NA

applies place value to order, read and represent numbers of up to five digits