Mathemagic!! Cheryl Miner Nebraska Wesleyan University

Binary Magic Pick a number 1 – 64 Which number cards does your number appear?

Think of a Number Think of a whole number Multiply by 2 Add 6 Add the square of your original number Subtract 5 Take the square root of your answer Tell me the answer Your original number is: _______

Divining Two Numbers Volunteer rolls a pair of dice Multiply the number on top of one die by 2 Add 3 to this. Multiply by 5 To this result, add the number on top of the 2 nd die Multiply this sum by 10 Tell me the result & I’ll tell you the two numbers rolled!

Select a number Double it Add 6 Divide by 2 Subtract your original number Your number is 3 Any algebraic identity may be used as the basis of a number game. Create your own trick for the equation:

Who’s Hiding the Coin 2-9 volunteers & assign number to each person Turn your back & have someone in group hide a coin in his/her left or right hand Have someone –Multiply the number of person concealing coin by 2 –Add 5 –Multiply by 5 –Add 10 –Add 1 if the coin is in the right hand or Add 2 if the coin is in the left hand –Announce the result Identify the person holding the coin and in which hand!

Who’s Hiding the Coin 2-9 volunteers & assign number to each person Turn your back & have someone in group hide a coin in his/her left or right hand Have someone –Multiply the number of person concealing coin by 2 –Add 5 –Multiply by 5 –Add 10 –Add 1 if the coin is in the right hand or Add 2 if the coin is in the left hand –Multiply by 10 –Add 1 for penny, 2 for nickel, 3 for dime, 4 quarter, 5 for half dollar, 6 for dollar –Announce the result Identify the person holding the coin and in which hand!

The Missing 8 Write down Volunteer: Place an “x” over the digit that you like the least Multiply by a number Answer: product will have all digits which match the number marked with the “x”

Gopher Magic -gopher-central.swf

Missing Digit 1.Pick a 5-digit number & multiply by 9 2.Write down the resulting number 3.Choose any digit (except zero) and circle it. 4.Find the sum of the remaining digits. 5.Tell me the sum. 6.Your missing digit is: _________

The Magic of 8 Multiply your phone number (without its area code) by the number 8 Write down: –The product from step 1 –Your 7-digit phone number –8 Add all the digits in 3 numbers If the sum is more than 1 digit, then add the digits in the sum. Continue adding up digits until only one digit is left.

49 - Lucky Number Cubes Find the following products: Top of Red * Top of White Bottom of Red * Bottom of White Top of Red * Bottom of White Bottom of Red & Top of White Add the results