A Cool Age and Change Trick
How would you like to guess the correct amount of change in someones hand. Now is the time to learn how to do that. While learning how to do the trick you will be practicing addition, subtraction, and multiplication.
Gather everyone together. Get a volunteer and have them hold some change. But making sure its less than a $1, £1 or whatever currency you using. All this time make sure that everyone can see that you not looking.
Bring out your pencil and paper or a calculator (use a pencil and paper ;))

Get your volunteer to multiply their age by two.

Add five to that total.

Multiply that new total by fifty.

Now Subtract 365 from the total.

Add the amount of change to the total.

Add 115.