The resources at the end of this article encompass a variety of ideas presented in kid-friendly fashion. everyday objects: Introduce students to a realm of mathematics they might never have heard of - topology - as they ooh and ahh over paper clips leaping and linking together when a dollar bill is snapped, or over the wonders of a Mobius strip.handmade cards with specially created sets of numbers.What do you get when you cut a Mobius strip in half?Â (a longer Mobius strip!) The first four digits are the year of your birth. When starting with 2, the new number is 222,222,222. (It's a string of nine digits made up entirely of each person's starting number. Surprise! Look at the number you have now! Multiply the magic number by your new number.

Some number tricks come back to a form of the starting number(s): Here is a magic number: 12,345,679 (Write it on the board.) The starting number appears in a final custom number. Reverse the digits and add this new number to the circled number. Subtract the smaller number from the larger one. Reverse the digits and write down this new number. The first and last digits should have a difference of more than one. (This trick works with numbers up to eight digits, when each digit is different.) (If you get a two-digit answer, add the two digits to get a single digit.) Subtract the smaller number from the larger.Īdd the digits in the difference. Mix up the digits to get another three-digit number. Write a three-digit number (with three different digits). One type of number trick involves adding, subtracting, multiplying, or dividing by a starting number and subtracting the original number in such a way that each participant always arrives at a certain number: Think of a number between 1 and 100.Īnother type of number trick involves rearranging and recombining digits: Operate on a starting number and always end up with a given number.

Abracadabra! Your number is 13! Images courtesy of Wendy Petti.

Magic calculator formula