Maths mate term 3 # sheet 5

n Maths mate: Term 3, Sheet 5

Problem 23: I think of a number, divide it by 2 then add 12. If the answer is 20, what was the original number?

 

Predict: I predict that I will use subtraction in this problem.

 

Clarify: nothing to be clarified

 

Find the big question: What was the original number?

 

Solve:

 

Since I have to reverse the process, because I have to find the original number, we will reverse the operations too.

The equation that they did was: __  / 2  + 12 = 20. But since we are reversing it we are doing subtraction and multiplication, because they are the opposite operation.

The equation that w are doing is: 20 – 12 x 2 = 16.

The answer is 16.

 

Summary: The math maticians toolboxthat I used in this sum was work backwards.


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