divisibility rules

2, 3, 4, 5, 6, 2, 3, 4, 5, 6, 9, 109, 10

““Divisible Divisible BYBY””

What does it mean?What does it mean?

““Divisible byDivisible by”” means: means:

If you divide one number by another, If you divide one number by another, the result is a whole number WITHOUT the result is a whole number WITHOUT a remainder.a remainder.

Examples:Examples:

12 12 ÷ 6 = 2 No remainder÷ 6 = 2 No remainder

15 ÷ 5 = 3 No remainder 15 ÷ 5 = 3 No remainder

Divisibility Divisibility Rule 2Rule 2

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

Examples:Examples: 7788 34734700

Review Review EvenEven numbers: numbers: ghosteven

NowNow You You Try:Try:Which number Which number IS NOTIS NOT

divisible by 2?divisible by 2?

572572 14641464 249249

Need More Practice: Numbers Divisible by 2

WONDERFUL

It ends in a 0, 2, 4, 6,

or 8.

Divisibility Divisibility Rule 3Rule 3

A number is divisible by three A number is divisible by three if the sum of the digits is if the sum of the digits is divisible by 3.divisible by 3.

Examples:Examples:75 7 + 5 = 12 12 75 7 + 5 = 12 12 ÷ ÷ 33 = 4 No = 4 No RemainderRemainder

369369 3 +6 + 9 = 18 18 ÷ 3 +6 + 9 = 18 18 ÷ 3 3 = 6 = 6 No RemainderNo Remainder

NowNow You You Try:Try:Which number Which number IS NOTIS NOT

divisible by 3?divisible by 3?

572572 14641464 279279

Need More Practice: Numbers Divisible by 3

The sum is divisible by

3.

WONDERFUL

Divisibility Divisibility Rule 4Rule 4A number is divisible by 4 if A number is divisible by 4 if the last two digits are the last two digits are divisible by 4.divisible by 4.

Examples:Examples:

13132020 20 20 ÷ 4 = 5÷ 4 = 5

667272 72 ÷ 4 = 1872 ÷ 4 = 18

NowNow You You Try:Try:Which number Which number IS NOTIS NOT

divisible by 4?divisible by 4?

564564 41014101 188188

Need More Practice: Numbers Divisible by 4

WONDERFUL

The last 2 digits are

divisible by 4.

Divisibility Divisibility Rule 5Rule 5

A number is divisible by 5 A number is divisible by 5 if the last digit is a 0 or if the last digit is a 0 or 5.5.

Examples:Examples:

616155 ends in a 5ends in a 5

14814800 ends on a 0ends on a 0

Now You Try:Now You Try:Which number Which number IS NOTIS NOT divisible divisible

by 5?by 5?

98209820 779 779 560560

Need More Practice: Numbers Divisible by 5

The number ends in a The number ends in a zero or a five.zero or a five.

WonderfulWonderful

Divisibility Divisibility Rule 6Rule 6

A number is divisible by 6 when it is A number is divisible by 6 when it is divisible by 2 divisible by 2 ANDAND 3. (prime 3. (prime numbers)numbers)

Examples:Examples:

408408 ends in an even number (2 ends in an even number (2 rule)rule)

sum of the digits is sum of the digits is divisible by 3divisible by 3

Review prime and composite numbers:Review prime and composite numbers: Prime and Composite Numbers

Now You Try:Now You Try:Which number Which number IS NOTIS NOT divisible divisible

by 6?by 6?

87008700 523523 7602 7602

Need more practice? Need more practice? Numbers Divisible by 6

Way To Go!!Way To Go!!

This number is This number is divisible by 2 and divisible by 2 and

3.3.

Divisibility Divisibility Rule 9Rule 9A number is divisible by 9 if A number is divisible by 9 if

the sum of the digits is the sum of the digits is divisible by 9.divisible by 9.

Examples:Examples:

963963 9 + 6 + 3 = 18 18 9 + 6 + 3 = 18 18 ÷ 9 = 2÷ 9 = 2

54455445 5 + 4 + 4 + 5 =18 18 5 + 4 + 4 + 5 =18 18 ÷ 9 =2÷ 9 =2

Now You Try:Now You Try:Find the number that Find the number that IS NOT IS NOT divisible by 9.divisible by 9.

98739873 636636 55415541

Need More Practice: Need More Practice: Numbers Divisible by 9 and 10

The sum of the digits The sum of the digits is divisible by 9.is divisible by 9.

Great Job!!!Great Job!!!

Divisibility Divisibility Rule 10Rule 10A number is divisible by 10 is A number is divisible by 10 is it ends in a ZERO.it ends in a ZERO.

Example:Example:

76376300 ends in a zeroends in a zero

414100 ends in a zeroends in a zero

Now You Try:Now You Try:Find the number that Find the number that ISIS NOT NOT divisibledivisible by ten.by ten.

56,92056,920 7537 7537870870

The number ends in a The number ends in a ZERO.ZERO.

Way To Go!!Way To Go!!

CongratulationCongratulations!s!

Complete two of the three Complete two of the three assignments. You may assignments. You may complete them on your complete them on your computers but print out your computers but print out your answer sheet.answer sheet.

Assignment 1.docAssignment 1.doc

chart.docchart.doc

assignment3.docassignment3.doc

CONGRATULATIONS ON CONGRATULATIONS ON HAVING ACHIEVED THIS HAVING ACHIEVED THIS

AIM.AIM.