Section 4.1 Divisibility and Factors Algebra Concepts Section 4.1 Divisibility and Factors

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

Is 72 divisible by 4?

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

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?

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

Justify your answer!!!!!

Are these numbers divisible by 10? Justify your answer.

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

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

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

This also works for 9!

#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?

Every number is divisible by 1!

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.