Algebra Concepts 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 2350 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 Number Divisible by 3? Sum of the digits 257 ? ? 3003 ? ? 456 ? ? 2146 ? ? 458 ? ? • Check each number

Divisible by 3 Number Divisible by 3? Sum of the digits 257 no 14 3003 yes 6 456 yes 15 2146 no 13 458 no 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 #2 #3 #4 #5 Is 234 divisible by 2? Is 3654 divisible by 3? Is 548 divisible by 5? Is 6902 divisible by 9? 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.