Slide 1: Ways to Check for Divisibility Divisibility Rules
Dividing By 1 : Dividing By 1 All numbers are divisible by 1
Now You Try : Now You Try Are these numbers divisible by 1? 578
398
48
1903
490
Dividing by 2 : Dividing by 2 All even numbers are divisible by 2
Even numbers are numbers that end with either 2, 4, 6, 8, or 0
Now You Try : Now You Try Are these numbers divisible by 2? 458
1279
759
555
1050
Dividing by 3 : Dividing by 3 Add up the digits of the number
If that number is divisible by 3, then the original number is
If your sum is still a big number, continue to add the digits
Dividing by 3 : Dividing by 3 If that number is divisible by 3, then the original number is If your sum is still a big number, continue to add the digits Add up the digits of the number 18 Is 18 divisible by 3? 1 + 8 = 9 Is 9 divisible by 3?
Now You Try : Now You Try Are these numbers divisible by 3? 639
56
86
360
468
Dividing by 4 : Dividing by 4 If the last 2 digits together are divisible by 4
Now You Try : Now You Try Are these numbers divisible by 4? 584
261
56
920
767
Dividing by 5 : Dividing by 5 If the number ends in 5 or 0
Now You Try : Now You Try Are these numbers divisible by 5? 554
6890
345
902
845
Dividing by 6 : Dividing by 6 If the number is divisible by 2, and . . .
If the number is divisible by 3
Now You Try : Now You Try Are these numbers divisible by 6? 897
258
630
345
84
Dividing by 7 : Dividing by 7
Now You Try : Now You Try Are these numbers divisible by 7? 578
398
48
1903
490
Dividing by 8 : Dividing by 8 If the last three digits are divisible by 8
If the number is divisible by 2,
then by 2 again, and then by 2 again
Now You Try : Now You Try Are these numbers divisible by 8? 568
396
48
1903
490
Dividing by 9 : Dividing by 9 Similar to dividing by 3
Add up digits
If that number is divisible by 9 then your number is divisible by 9
Dividing by 9 : Dividing by 9 If that number is divisible by 3, then the original number is If your sum is still a big number, continue to add the digits Add up the digits of the number 27 Is 27 divisible by 9? 2 + 7 = 9 Is 9 divisible by 9? For example, take the number 924,561
Now You Try : Now You Try Are these numbers divisible by 9? 578
398
48
1903
490
Dividing by 10 : Dividing by 10 If the number ends with a 0
Now You Try : Now You Try Are these numbers divisible by 10? 578
398
48
1903
490
Dividing by 11 : Dividing by 11
Now You Try : Now You Try Are these numbers divisible by 11? 578
398
48
1903
490
REVIEW : REVIEW Divisible by 1
Divisible by 2
Divisible by 3
Divisible by 4
Divisible by 5
Divisible by 6 Divisible by 6
Divisible by 8
Divisible by 9
Divisible by 10
Divisible by 11
Assignment : Assignment Tell what each number is divisible by, either 2, 3, 4, 5, 6, 7, 8, 9, 10, or 11 186
85
69
298
747 3870
7896
69095
4892
3487 952
3650
2738
1132
5084
Slide 28: That's all Folks!