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Using number lines in Addition and Subtraction By Amani El-Alawneh

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Adding numbers using the number line So how do we do this using the number line?

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We use the strategy called: Counting Up You need to think about: What number shall I start with on my number line? What number do we want to count up by? Are there any number bonds that can help me?

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= Use the counting up method!! So we start at the biggest number…47 And count up 25 places What number do we end on??? So… =

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Use the Counting Up Strategy Remember -You need to think about: What number shall I start with on my number line? What number do we want to count up by? Are there any number bonds that can help me? + 34 = 57 ?

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So what is = 23 So… = = 57

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Can I use the counting up strategy for Subtraction too? Have a look at this question! 43 – 27 = What number shall I start from on my number line? 27 What number shall count on by? Can any number bond make counting on easier for me? = What number do I want to get to? YES

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32 - = 18 What number shall I start from on my number line? What number do I want to get to? What number shall count on by? Can any number bond make counting on easier for me? = 14 So… = 18 14

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Have a go at these questions now using number lines and the counting on strategy: 1.45 – 25 = 2.54 – 26 = 3. – 19 = – = – 37 = = = = = = Extra for Experts: – – – –

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Work out the following calculations mentally: 43 – – – – 2997

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How can we show this using the number line: – = 6 So, 43 – 37 = – = 7 So, 154 – 147 = 7

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Have a look at these Calculations 144 – – – What is it about the numbers that made you decide to use mental method or a number line? Do you always need to use a number line when the numbers are a long way apart??

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- 285 =

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