Trick 1: The Great MATHoudini

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

……………………………………………………………………………………

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.

Example:

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

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

Mathspig tried the m&m Algebra Challenge in her ICME 13 Workshop in Hamburg.

BUT … I bought PEANUT m&ms. OH Nooooooooo!

They were the WRONG SHAPE. Deformed m&ms bounced everywhere. All I could do was collect the m&ms in my gloved hands and hand them out to the workshop participants. They seemed to enjoy the failure.

But Mathspig does not give up that easily.

Here is the m&m ALGEBRA CHALLENGE with PLAIN m&ms.

The Great m+m ALGEBRA CHALLENGE

Method:

1. Open a packet of PLAIN m&ms. (Wear white Gloves like the m+ms)

2. TIP onto table. (Put a few books around the edge to define an area.)

3. Sort the m&ms into:

…m -UP pile.

…m-DOWN pile.

4. REMOVE the m-UP pile.

5. PICK up m-DOWN pile and TIP again.

6. REPEAT until only 1 m+m is left.

The pattern should follow the exponential equation here:

Did it work? Check it out below.

Who knew one family packet had 366 m+ms?

You’ll find a worked ‘theoretical’ example here.

Here’s the ANSWER:

Try it. Middle school students have to see

that applying maths in the real world can be tricky but logical.

And a lot of FUN too.

Lego Algebra

This Lego Algebra is designed as s a demonstration, rather than a student activity.

Let x = no. of Lego Bricks.

Now find x:

 

 

Don’t forget there is a lot of algebra fun on Mathspig with Algee Baa: Algebra for Beginners