Thursday, October 8, 2009

Multiples of nine





To know if a number is a multiple of nine you must add up all the digits and if the sum equals three or nine the whole number is, But if the sum equals a two or more digit number you add those up to get a sum of 3 or nine.

1 comment:

  1. I did not know the mathematical "secret" you taught today in class. I am going to show your lesson to my Math 12 class. They will be impressed!

    ReplyDelete