a

Lorem ipsum dolor sit amet, conse ctetur adip elit, pellentesque turpis.

Image Alt

Divisibility Rules: No, it’s Not Cheating

  /  Divisibility Rules: No, it’s Not Cheating

Divisibility Rules: No, it’s not Cheating!
By Lisa Williams

These rules are useful for kids from the time they start division, on. They keep me from using a calculator and most of the time, I can even work it in my head faster than the calculator because of these rules. I use them most when reducing awkward fractions.

To Divide by …
Cheat Codes
2 A number is divisible by 2 if it ends in 0 or an even number.Example:   40 divided by 2 = 20 

           3974 divided by 2 = 1987
.

3 A number is divisible by 3 if the sum of the digits is divisible by 3.Example: 321 add 3+2+1= 6 so 321 divided by 3 = 107

   2460 add 2+4+6+0= 12 so 2460 divided by 3 = 820

4 A number is divisible by 4 if the last 2 digits are both zeros or if they are divisible by 4.Example:  300 divided by 4 = 75

               3548 divided by 4 = 887

5 A number is divisible by 5 if it ends in 0 or 5.Example:  25 divided by 5 = 5

               400 divided by 5 = 80

6 A number is divisible by 6 if it is even and divisble by 3.Example: 246 is even and 2+4+6 = 12 so 246 divided by 6 = 41
9 A number is divisible by 9 if the sum of the digits is divisible by 9.Example: 81 add 8 + 1= 9 so 81 divided by 9 = 9

     972  add 9+7+2 = 18 so 972 divided by 9 = 18

10 A number is divisible by 10 if it ends in 0.Example: 400 divided by 10 = 40

For more articles by this Consultant Click Here
For more articles on Grade 5 Mathematics Click Here