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2. Add 12 Answer 6 Add 8 Add 2 Answer 4 Answer 1
Mrs Calculus, the maths teacher was playing a number game with her year 7 class. She said to Robert: Think of a number Double it Add Half it Subtract the number thought of Your answer is 6
Add 12
Answer 6
Add 8
Add 2
Answer 4
Answer 1
Robert was surprised when she got it correct. She did it twice more with Gemma and Saeed when she asked them to add 8 and 2 and she got the right answer again both times.
She then did it with the whole of the class at the same time (add 20) and she was right again. Everyone was amazed!!

3. Add 12 Answer 6 Add 8 Add 2 Answer 4 Answer 1
Mrs Calculus, the maths teacher was playing a number game with her year 7 class. She said to Robert: Think of a number Double it Add Half it Subtract the number thought of Your answer is 6
Add 12
Answer 6
Add 8
Add 2
Answer 4
Answer 1
Investigate this number trick by doing it yourself with some chosen numbers. Explain why it works for any number n.

4. Add 12 Answer 6 Add 8 Add 2 Answer 4 Answer 1
Mrs Calculus, the maths teacher was playing a number game with her year 7 class. She said to Robert: Think of a number Double it Add Half it Subtract the number thought of Your answer is 6
Add 12
Answer 6
Add 8
Add 2
Answer 4
Answer 1
It would appear that the answers is always half of the number that Mrs Calculus asks the students to add. She also seems to ask them to add an even number every time.

5. Mrs Calculus, the maths teacher was playing a number game with her year 7 class. She said to Robert: Think of a number Double it Add Half it Subtract the number thought of Your answer is 6
n 2n  2n + e  n + ½e  ½e
even number
It would appear that the answers is always half of the number that Mrs Calculus asks the students to add. She also seems to ask them to add an even number every time.