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2.04 Numbers near 100, 1000, 10000


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When we count on a number line, counting by 10's or finding numbers that can make 10 will help us.


Drag the slider to different numbers to see different pairs that add to 10.

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Each number from 0 to 10 can be added to another number to get 10.


Example 1

Which of the following pairs of numbers add to 10?

3 and 7
2 and 8
5 and 5
1 and 9
Worked Solution
Create a strategy

Add each pair of numbers.

Apply the idea
\displaystyle 3+7\displaystyle =\displaystyle 10Add Option A
\displaystyle 2+8\displaystyle =\displaystyle 10Add Option B
\displaystyle 5+5\displaystyle =\displaystyle 10Add Option C
\displaystyle 1+9\displaystyle =\displaystyle 10Add Option D

All of the options add to 10.

Idea summary

Each number from 0 to 10 can be added to another number to get 10.

Count by 2, 5, 10

When we are counting, what happens when our number moves from the tens to the hundreds? In this video, we see how to continue counting by 1,2,5, or 10. We also look at how to count from hundreds to thousands, and thousands to tens of thousands.

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Example 2

Using the image of the number line below, what is the next number in the pattern?

A number line with skip counting from 988. Ask your teacher for more information.

988,\, 993,\, 998,\, ⬚

Worked Solution
Create a strategy

Count the number of jumps from the first number to the second number.

Apply the idea

We can see from the number line that the first arrow begins at 988, the second at 993, and the third at 998, and the last at 1003.

Each number has 5 jumps between them, so they all belong in the same pattern. So the complete number is:

988,\, 993,\, 998,\, 1003

Idea summary

When we count with numbers near 100, 1000, or 10\,000, a number line is really useful to see where we end up.

We can also break apart numbers in different ways, in order to help us count. Like in the image below, we could add 2 and then add 3, or we can add 5 in one jump.

Number line from 190 to 210 shows adding 2 then 3 to 198 to jump to 203.
Number line from 190 to 210 shows adding 5 to 198 to jump to 203.



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

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