1. Section 4.1 Divisibility and Factors
Algebra Concepts
Section 4.1
Divisibility and Factors

2. Divisible- describing two numbers when one number is divided by another number and the remainder is 0
12 is divisible by 6
200 is divisible by 10

3. Is 72 divisible by 4?

4. Divisible by 2 Numbers that end in 0,2,4,6 or 8.
In other words – even numbers!

5. Divisible by 5 55 is divisible by 5 630 is divisible by 5
342 is not divisible by 5
486 is not divisible by 5
When is a number divisible by 5?

6. Divisible by 10 All the numbers in the bottom row are divisible by 10
What do they have in common?

7. Justify your answer!!!!!

8. Are these numbers divisible by 10? Justify your answer.

9. Divisible by 3 Check each number Number Divisible by 3?
Sum of the digits
257 ?
3003
456
2146
458
Check each number

10. Divisible by 3 Check each number Number Divisible by 3?
Sum of the digits
257 no 14
3003
yes 6
456 15
2146 13
458 17
Check each number

11. If the sum of all the digits is divisible by 3, the number will be divisible by 3!!
Works every time!!!!

12. This also works for 9!

13. #1 Is 234 divisible by 2. #2 Is 3654 divisible by 3
#1 Is 234 divisible by 2? #2 Is 3654 divisible by 3? #3 Is 548 divisible by 5? #4 Is 6902 divisible by 9? #5 Is 2000 divisible by 10?

14. Every number is divisible by 1!

16. Factor-a number that divides evenly into another number
To find all the factors, start with one and find all the numbers that go into the larger number.
Every factor has a partner that gives you the larger number as a product.