# Divisibility Rules!.

## Presentation on theme: "Divisibility Rules!."— Presentation transcript:

Divisibility Rules!

What is Divisibility? Divisibility means that after dividing, there will be no remainders. The divisor can evenly divide into the dividend.

356,821 The divisibility rules can help you!
Can you tell by just looking at this number if it is divisible by 2? by 3? by 4? by 5? by 6 ? by 9? By 10? The divisibility rules can help you!

Divisibility rules help you learn shortcuts to tell when a number can be divided by another number without any remainders.

Divisibility by 2 18 ÷ 2 = 9 A number is divisible by 2
if the number is even. 18 ÷ 2 = 9 22 ÷ 2 = 11 (18 and 22: Notice that both of these dividends are even.) 21 ÷ 2 = 10 R1 (21: not an even number.)

Are these numbers divisible by 2?
Now You Try Are these numbers divisible by 2? 79,458 1,279 6,249 51,553 19,050 35,792

Divisibility 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: = 9 Yes, 135 is divisible by 3 because the sum of the digits is divisible by 3.

For example, take the number 738
Dividing by 3 For example, take the number 738 Add up the digits of the number 7 + 3 8 = 18 Is 18 divisible by 3? If that number is divisible by 3, then the original number is Oh yeah! If your sum is still a big number, continue to add the digits 1 + 8 = 9 Is 9 divisible by 3?

Are these numbers divisible by 3?
Now You Try Are these numbers divisible by 3? 639 56 86 360 468 2,511

If the last 2 digits together are divisible by 4
Dividing by 4 If the last 2 digits together are divisible by 4 Example: 72,624 Is 24 divisible by 4? Great scott

Are these numbers divisible by 4?
Now You Try Are these numbers divisible by 4? 97,584 123,261 48,156 53,920 25,767 13,224

Divisibility by 5 A number is divisible by 5 if it ends in 0 or 5. 25 ÷ 5 = 5 23 ÷ 5 = 4 R3

Are these numbers divisible by 5?
Now You Try Are these numbers divisible by 5? 198,554 6,890 31,345 68,902 371,845 20,001

Divisibility by 6 A number is divisible by 6
if it is divisible by both 2 AND 3. Is 42 divisible by 6? Think: Is 42 divisible by 2? Is 42 divisible by 3? Is 51 divisible by 6? Hint: Is it an even number?

Are these numbers divisible by 6?
Now You Try Are these numbers divisible by 6? 897 258 630 345 84 8,235

Divisibility by A number is divisible by 9 if the sum of its digits is divisible by 9. 369 is divisible by 9 because =18 1 + 8 = 9 and 9 is divisible by 9.

Dividing by 9 Add up the digits of the number 27 9 + 2 4 6 5 1 =
For example, take the number 924,561 Add up the digits of the number 27 9 + 2 4 6 5 1 = Is 27 divisible by 9? If that number is divisible by 3, then the original number is Oh yeah! If your sum is still a big number, continue to add the digits 2 + 7 = 9 Is 9 divisible by 9?

Are these numbers divisible by 9?
Now You Try Are these numbers divisible by 9? 55,578 22,398 91,548 17,903 32,490 83,402

Divisibility by A number is divisible by 10 if it ends in 0.
30 ÷ 10 = 3 340 ÷ 10 = 34 67 ÷ 10 = 6 R7 784 ÷ 10 =78 R4

Are these numbers divisible by 10?
Now You Try Are these numbers divisible by 10? 24,578 39,800 48,003 19,030 490,870 65,432

Is it divisible by: 2 3 4 5 6 9 10 444,555,448 26,350 74,673,042 61,616,168 732,510 9,623,205

Is it divisible by: 2 3 4 5 6 9 10 123,456,789 58,468,240 52,301,042 246,813,579 135,790,135 813,423,700

After all, divisibility rules!

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