## Friday, December 26, 2008

### Divisibility tests

Two (2)
A number is divisible by two if it is even. Another way to say a word is even is to say it ends in 0, 2, 4, 6 or 8. 682 is divisible by two because it ends in a two, which makes it an even number

Three(3)
A number is divisible by three if the sum of the digits adds up to a multiple of three. 423 is divisible by three because 4 + 2 + 3 = 9.Since nine is a multiple of three (or is divisible by three), then 423 is divisible by three

Four (4)
A number is divisible by four if it last two digits are divisible by four . 4436 is divisible by 4 as last two digits 36 is divisible by 4

Five (5)
A number is divisible by five if it ends in a five or a zero. 5365 is divisible by five because it ends in a five

Six (6)
A number is divisible by six if it is divisible by both two and three.444 is divisible by six because it is even, so it is divisible by two and
its digits add up to six,which makes it divisible by three

Nine (9)
A number is divisible by nine if the sum of the digits adds up to a multiple of nine. This rule is similar to the divisibility rule for three.
9243 is divisible by nine because the sum of the digits adds up to eighteen, which is a multiple of nine

Ten (10)
A number is divisible by ten if it ends in a zero. This rule is similar to the divisibility rule for five.