Subtraction by counting on

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Subtraction by counting on

• Key Words
• Subtraction taking away

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Lesson Aim To know how to subtract numbers to
100 by counting on
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How do you solve 99-45 by counting on?

• 45
• 99 ?

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We count on.
Here is how..
Think !
5
99-45544555050409090999
We added 5409 54
add 5 add 40
add 9
45 50
90 99
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Counting on always starts with the number being
taken away
ends with the number that has something taken
away from it
WE find the DIFFERENCE between the two numbers.
If you need more help please ask now..
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Solve these by counting on
78-89 94-56 67-53 88-32