Posts Tagged ‘spooky’

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Trick 4: How to be a Mathematical Clairvoyant

June 22, 2018

How to be a Mathematical Clairvoyant

Requirements: Spooky music and spooky look.

You will find some spooky music here.

Tell your students you will beat them  adding up 5 x 5 digit numbers in your head when they are using calculators.

Method:

1. Ask a student to write down 2 x 5-digit numbers on the board.

2. You rapidly write a 5-digit number underneath.

3. Ask another student to write another 5-digit number.

4. You write another 5-digit number quickly.

5. You have 5 by 5 digit numbers. Say ‘Go’. You instantly write down the answer.

Stand back.

This is how it works:

N1 = 97413

N2 = 28619

N3 = 71380  (Each digit in N3 that you write down must add up to 9 with digits in No. above)

N4 = 64231

N5 = 35768  (Once again each digit in N5 must add up to 9 with digits above)

Now you will instantly write down the sum of these five numbers as

297411

Da! DA!

The trick is to subtract 2 from N1 and put it in front:

N1 = 97413

N1 -2 = 97411

Sum of 5 numbers = 297411

This is why it works:

Hint: When you get your students to add up the five 5-digit numbers on a calculator you will beat them, but they will also get many different answers as a number of students will key incorrect numbers.

Magic Chat

 

 

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Trick 6: Freaky Math Medium

May 27, 2018

Write the word carrot inside your math text book. Do not show students.

When Mathspig was a mathspiglet we used to play this trick. It doesn’t work on everyone, but it works  often enough.

Ask a student to say 15 times 15 fifteen times.

Then ask them to name a vegetable. Students say carrot 90% (I’m guessing) of the time.

To make this trick more dramatic send 10 students out of the class before you begin and tell the other half what you are about to do. Students return one at a time. How often do they say ‘carrot’? What % of students say carrot? 

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Trick 8: Spooky Maths Magic

May 4, 2018

Spooky Maths Magic

Requirements; Smart board/data projector.

 This is mental maths, but not hard maths. You can play this video by Marco Frezza  directly to the class.

It may not work on everybody, but it would be very interesting to see how many students are fooled by this spooky magic man.