What is Divisibility? Divisibility means that after dividing, there will be No remainder.
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Transcript of What is Divisibility? Divisibility means that after dividing, there will be No remainder.
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What is Divisibility? Divisibility means that after dividing, there will be No remainder.
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356,821Can you tell by just looking at this number if it is divisible by 2?
by 5? by 10? by 3 ?by 9?By 6?
The divisibility rules can help
YOU!
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Divisibility Rules help you learnhelp you learn
shortcuts to tell when to tell when a number can be a number can be
divided by another divided by another number with number with
NO REMAINDER..
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Dividing By 1All numbers are divisible by 1
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Now You TryAre these numbers divisible by 1?
a) 578b) 1201c) 465
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Dividing by 2All even numbers are divisible by 2
Even numbers are numbers that
end with either 2, 4, 6, 8, or 0
18 ÷ 2 = 9 22 ÷ 2 = 11
Notice that both of these numbers are even.
21 ÷ 2 = 10 R1 NOT EVEN
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Now You TryAre these numbers divisible by 2?
a) 458b) 1279c) 759
Not an even number
Not an even number
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Dividing by 3 A number is divisible by 3 if the sum of the digits is divisible by 3.
Is the number 135 divisible by 3?
Add the digits: 1 + 3 + 5 = 9
Yes, 135 is divisible by 3 because the sum of the digits is divisible by 3.
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Now You TryAre these numbers divisible by 3?
a) 639Sum of 6+3+9 =18
b) 56 Sum of 5+6 =11 NO
c) 738Sum of 7+3+8 =18
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Dividing by 4If the last 2 digits together are divisible
by 4
or take your number, divide it by 2. Then divide that answer by 2, and if you get an EVEN NUMBER then it is divisible by 4
2)360180 EVEN
2)180 90 EVENExample
360
4)84 21
Example
384
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Now You TryAre these numbers divisible by 4?
a) 584
b) 261
4)84 21
4)61 15 r1 NO
Take the last 2 digits and divide by 4
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Dividing by 5If the number ends in 5 or 0
25 ÷ 5 = 5 23 ÷ 5 = 4 R3 NO
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Now You TryAre these numbers divisible by 5?
a) 554
b) 6890
c) 345
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Dividing by 6If the number is divisible by 2,
AND . . .
If the number is divisible by 3
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Now You TryAre these numbers divisible by 6?
a) 897
b) 258
c) 630
No it is not EVEN
EVEN, Sum of 2+5+8 =15 EVEN, Sum of 6+3+0 =9
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Dividing by 7
There is no special rule to help you know if a number is divisible by 7…
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Now You TryAre these numbers divisible by 7?
a) 500b) 49c) 2100
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Dividing by 8 If the last three digits are divisible
by 8 If the number is divisible by 2, then by 2 again, and then by 2 again
So what type of number does it have to be?
3 2 8
2 2 2 = 8
A number that has been cubed.
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Now You TryAre these numbers divisible by 8?
a) 568 2)568 284 Even
2)284142 Even
2)142 71
b) 396 2)396 198 Even
2)19899 Odd
NO
Take the last 3 digits and divide by 2, then divide by 2,
then divide by 2
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Dividing by 9Similar to dividing by 3
Add up digits
If that number is divisible by 9 then your number is divisible by 9
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Dividing by 9
If that number is divisible by 9, then the original number is
If your sum is still a big number, continue to add the digits
Add up the digits of the number 27
Is 27 divisible by 9?
2 + 7 = 9
For example, take the number 924,561
9 + 2 + 4 + 6 +5 + 1 =
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Now You TryAre these numbers divisible by 9?
a) 578
b) 399
c) 144
Sum of 5+7+8 =20 NO Sum of 3+9+9 =21 NO Sum of 1+4+4 =9
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Dividing by 10If the number ends with a 0
30 ÷ 10 = 3340 ÷ 10 = 3467 ÷ 10 = 6 R7784 ÷ 10 =78 R4
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Now You TryAre these numbers divisible by 10?
a) 5782b) 390c) 45
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Dividing by 11There is no special rule to help you know if a number
is divisible by 11…
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Now You TryAre these numbers divisible by 11?
a) 99
b) 88
c) 121
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REVIEW
Divisible by 1
Divisible by 2
Divisible by 3
Divisible by 4
Divisible by 5
Divisible by 6
Divisible by 7
Divisible by 8
Divisible by 9
Divisible by 10
Divisible by 11
Thumbs up if you remember the rule.
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After All… DIVISIBILITY Rules
Take Out Your Study Guide!!!
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RULES FOR DIVISIBILITY#1
A Number Is Divisible By: IF 2 3 4 5 6 8 910
The last digit is even (0, 2, 4, 6, 8)
The last 2 digits are divisible by 4
The sum of the digits is divisible by 3
The last digit is 0 or 5
It is divisible by 2 and 3
The last 3 digits are divisible by 8
The sum of the digits is divisible by 9
The last digit is 0
(÷2÷2÷2)
(÷2÷2)
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IS THE NUMBER DIVISIBLE EXACTLY BY?
WRITE yes (y) or no (n) REMEMBER: Show the sums for 3, and show the division for 4 and 8.
Number2 3 4 5 6 8 9 10
1)
360 y3+6 = 9
yy
y y
2)360180
2)180 90
yy y
2)6030
2)3015
2)90 45
#2