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Australia
Year 5

1.02 Order numbers

Lesson

Are you ready?

Before we try and order 6-digit numbers, check if you remember how to order 5-digit numbers.

Examples

Example 1

Which number is the smallest?

A
88\,588
B
88\,888
Worked Solution
Create a strategy

Use a place value table and compare the digits from ten thousands.

Apply the idea
Tens of ThousandsThousandsHundredsTensOnes
88588
88888

We can see both these numbers have the same number of ten thousands and thousands, so we move onto the hundreds column.

We can see that 88\,588 has a smaller number in the hundreds columns. So the correct answer is A.

Idea summary

We can use a place value table to compare 5 digit numbers. 5 digit numbers start in the tens of thousands column and have a digit in each column down to the ones.

Order numbers up to millions

In this video, we see how to order numbers in ascending order. We also see how to order numbers where we have numbers with 7 digits, and numbers with only 6 digits.

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Examples

Example 2

We want to arrange the following numbers in ascending order:

491\,476,\,\,793\,340,\,\,633\,284

a

Which number comes first?

A
633\,284
B
491\,476
C
793\,340
Worked Solution
Create a strategy

Use a place value table and compare the digits from the hundred thousands.

Apply the idea

The numbers in a place value table is shown below:

Hundred thousandsTen thousandsThousandsHundredsTensOnes
491476
793340
633284

We can see that all the numbers are different in the hundred thousands column.

491\,476 has the smallest value of hundred thousands so it is the smallest number.

So the correct answer is B.

b

Which number is the second number?

A
793\,340
B
491\,476
C
633\,284
Worked Solution
Create a strategy

Use the place value table from part (a) and compare the digits from the hundred thousands.

Apply the idea

6 is next smallest number in the hundred thousands column, so 633\,284 is the second largest number in the list.

So the correct answer is C.

c

Which is the third number?

A
793\,340
B
491\,476
C
633\,284
Worked Solution
Create a strategy

Choose the number that has not been chosen yet.

Apply the idea

The only number left is 793\,340. So the correct answer is A.

Idea summary

To determine the largest or smallest number in a pair, or set, of numbers, we can compare the furthermost left place value digits. If they are the same, we move to the right, one place at a time, until they are different.

We can also use the 'greater than' (\gt) or 'less than' (\lt) symbol to compare two numbers, remembering that the 'greater than' sign has the big part towards the larger number, and the 'less than' symbol has the small part towards the smaller number.

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