1. Divisibility Rules and Number Theory
5-Minute Frenzy
Math Notebook
Divisibility Rules and Number Theory
Schedule:

2. Add to your Table of Contents:
Multiplication Pg. 3
Division Pg. 4
Divisibility Rules Pg. 5

3. 12 ÷ 6 = 2 15 ÷ 5 = 3 “Divisible by” means:
It goes into the other
number without a remainder!
Examples:
12 ÷ 6 = ÷ 5 = 3

4. Number: 2
A number is divisible by 2 if the last digit is even. (0, 2, 4, 6, 8) Examples:

5. Now You Try: 572 1464 249 Need More Practice: Numbers Divisible by 2
Which number IS NOT divisible by 2?
Need More Practice: Numbers Divisible by 2

6. Number: 3
*Hint add the digits and see if you can divide that number by 3
Examples:
7 + 5 = ÷ 3 = 4

7. Circle all of the numbers
That are divisible by 3! 20 42 48 39 35 24 6 30

8. Number: 5
A number is divisible by 5 if the last digit is a 0 or 5. Examples: 615 ends in a ends on a 0

9. Now You Try:
Which number IS NOT divisible by 5?

10. Number:10
A number is divisible by 10 is if it ends in a ZERO. Example: 7630 ends in a zero 410 ends in a zero

11. Find the number that IS NOT divisible by ten.
Now You Try:
Find the number that IS NOT divisible by ten.
56,

12. Number: 4
A number is divisible by 4 if the last two digits are divisible by 4. Examples: ÷ 4 = ÷ 4 = 18

13. Which number IS NOT divisible by 4?
Now You Try:
Which number IS NOT divisible by 4?
Need More Practice: Numbers Divisible by 4

14. Number: 6
A number is divisible by 6 when it is divisible by 2 AND 3. Examples: 408 ends in an even number (2 rule) sum of the digits is divisible by 3

15. Which number IS NOT divisible by 6?
Now You Try:
Which number IS NOT divisible by 6?

16. Number: 9
A number is divisible by 9 if the sum of the digits is divisible by 9.
Example: 963
= 18
18 ÷ 9 = 2

17. Number Theory
What does that mean?

18. What is an even number? Can be divided by 2
Unit digit is 0, 2, 4, 6, or 8
Is a multiple of 2
782,444 4
608

19. What is an odd number? Cannot be divided by 2
Unit digit is 1, 3, 5, 7, or 9
Is not a multiple of 2
782,333 5
607

20. EVEN + EVEN = ?
12 + 4

21. ODD + ODD = ?
11+9

22. EVEN + ODD = ?
8+7

23. Number Theory…