Write an article based on this "Tell someone to pick a number from 1-9 without telling you. Have them multiply their number on a calculator by "9," then by "12345679. Make them show you the results or pass you the calculator. Look at the number to determine what their original number was and tell them."
Explain to them that you are going to tell them what number they chose at the end. Put on an act that you are reading their mind while they are thinking of a number. This is a super easy math trick that is easy to figure out at the end, but it's still fun to put on a show! " Notice that there is no "8" in the second sequence of numbers. Make sure they multiply the number they chose by "9", then by "12345679," with no "8" in order for the trick to work. Keep pretending you are reading the person's mind while they perform the multiplication. Tell them you will divide what number they chose at the beginning from the result on the calculator. Have them hold the calculator to face you so you can see the number or hand it to you so you can look. If you have an audience, don't let them see the result on the screen in order to create a more dramatic effect. Whatever number you see repeating on the screen is the number they chose at the beginning. There will only be a string of a single repeating number. For example, if they chose "1," then the calculator will show "111111111."