Topics
2. Forwards and backwards
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Australia
Year 3

2.02 Count by 10's, 100's

Lesson
Practice
Lesson

Are you ready?

Do you remember the  names for each place in a number  , up to the thousands?

Idea summary
A name for each place value from ones to thousands. Ask your teacher for more information.

Count by 10's

Let's see how we can count by 10's, using a 100 grid.

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Examples

Example 1

Complete the pattern by adding 10 each time.

20,⬚,40, ⬚, ⬚

Worked Solution
Create a strategy

Use the place value table to add 10 to each number.

Apply the idea

Put 20 in the place value table and add 10.

TensOnes
20
+10
Result30

The amount in the tens place goes up by one and we get a result of\,30. The ones value does not change. We add ten again to complete the pattern by adding 1 to the tens place each time.

The complete pattern is 20,\,30,\,40,\,50,\,60.

Count by 100's

Now it's time to count by 100's.

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Examples

Example 2

Complete the pattern by adding 100 each time.

9,109,⬚,⬚, ⬚, 509

Worked Solution
Create a strategy

Use the place value table to add 100 to each number.

Apply the idea

Put 109 in the place value table and add 100.

HundredsTensOnes
109
+100
Result209

The amount in the hundreds place goes up by one and we get a result of\,209. The ones and tens values do not change. We add 100 again to complete the pattern by adding 1 to the hundreds place each time.

The complete pattern is 9,\,109,\,209,\,309,\,409,\,509.

Idea summary
A pattern of numbers that go up by 10. Ask your teacher for more information.
A pattern of numbers that go up by 100. Ask your teacher for more information.

Outcomes

ACMNA052

Recognise, model, represent and order numbers to at least 10 000

ACMNA053

Apply place value to partition, rearrange and regroup numbers to at least 10 000 to assist calculations and solve problems

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