Posts Tagged ‘surprising’


Trick 1: The Great MATHoudini

September 18, 2018

The Great MATHoudini

Requirements: 1 phone book, Great showmanship

Start by handing one member of the class a sealed envelope. It contains a name that you have seen in your mathematical mind.

All will be revealed at the end of the performance.

Ask one student to write a 3-digit number on the board.

Ask a second student to turn this number around and subtract the smallest number from the largest number.

Ask a third student to turn that number around and add the last two numbers.

Example: N1 = 371.

N2 = 173

N1 – N2 = N3 = 371 – 173 = 198

N4 = 891

N4 – N3 = 891 + 198 = 1089

Give a fourth student a phone book. Ask them to go to page 108 and count down 9 places on the first column and read out the name.

Now open the envelope.

Da! Da!


How does it work? The numbers ALWAYS add up to 1089 so you had plenty of time to check out the name in the phone book.

Source: Magic/Menatalism Tips and Tricks


Trick 2: The Math Teacher Knows

August 4, 2018


The Math Teacher Knows Everything

Requirements: 1 die, a fanfare would be nice.

You will find a fanfare here.

Ask a student to roll the die, double the number and add 5.  He can show the class the number, but not you.

Ask the student to multiply this number by 5.

Ask the student to roll the die again and add this number to the total.

Now you can tell them the numbers they rolled.


N1 = 3

Double: 2N1 = 6

Add 5: 2N1 + 5 = 11

x5:   5(2N1 + 5) = 55

Roll dice:

N2 = 4

Add 4:

55 + 4 = 59

The Math Teacher Knows:

Secretly subtracts 25 from this number:

59 – 25 = 34

Da! Da! There are the two numbers rolled.

Source: Magic/Menatalism Tips and Tricks



April 16, 2018


There are 10 math questions

(pdf version and pdf ans below).

The boxed sections are keyboard math symbol shortcuts.

When the students push these keys the Qs finally make sense.

eg. option v = square root sign


1. They must have a computer with a KEYBOARD (not a tablet)

2. The computer must be a MAC*

*Mathspig tried to find the QWERTY Math shortcuts on her old PC and it went crazy!!!! 

QWerty Math for MAC pdf

Qwerty Math for MAC ANS


5. Funky, Fab and Fantastic. Yeah! That’s Middle School Maths

September 20, 2016


Funky, Fab and Fantastic INTRO

Algebra! Many students struggle with algebra because they see no point doing it. But here is the best fun with algebra you’ll ever have. It is so counter intuitive that you have to see the algebra to believe this trick. Mathspig tried this exercise out on school teachers at her ICME 13  workshop in Hamburg and this is the result filmed – with a few lighting wobbles – on an iphone.

Detailed explanation here.