Here's a recipe for making your own 3 X 3 magic number square. So do both diagonals!īack to Top A Recipe for Your Own 3 X 3 Magic Square So do both diagonals!Įvery row and column sums to 34 in this magic square. This is possible because the middle digit will always be 9, and the other two digits will always sum to 9! So to get the digit other than the middle one (which is 9) and other than the digit that your friend tells you, just subtract the digit your friend tells you from 9, and that is the unknown digit.Įvery row and column sums to 15 in this magic square. Tell your friend that if she or he will tell you what the first OR last digit of the answer is, you will tell her or him what the other two digits are.The sum of the three digit answer will always be 18! Then amaze him or her by teling them what the sum of those three numbers is.

Ask your friend to add up the three digits of the number that results from subtracting the smaller from the larger 3-digit number.

Tell them not to tell you what the result is.

Now have him or her subtract the lower (and smaller) 3-digit number from the upper (and larger) 3-digit number.

And write this number right underneath the first number.

Next have her or him form a new 3-digit number by reversing the digits, putting the smallest first and the largest last.

Tell him/her not to tell you what the numbers are.

Tell him or her (or her or him) to write the three numbers down next to each other, largest first and smallest last, to form a single 3-digit number.

Ask your mark to pick three (3) different numbers between 1 and 9.

(But remember we were first.)Īmaze the peons with this one.

If you want more math challenges try the new PBS MATHLINE MATH CHALLENGESsite.

Explore Geometryin a fun and interactive way.

Test your knowledge of the multiplication tables ().

(If you're using Netscape, Do Not Scroll down the page while this loads.

Play a Math-Chase Game () - for one or two players.

Learn about the original computer: The Abacus ().

A Reading list of Tricky Math Books, most of which I have used for this site.

Idea that math can be fun! Try these tricks: Math Tricks for All Ages This web page is devoted to the

1+2+3+1 1+2+3+1 1+2+3+1=? brain out