How Do I find out if a number is divisble or not?? PLEASE HELP!!! ?

Question

If I have a number: 843,720, and the question asks what number is NOT dicisble by which of the following?

A: 2

B: 3

C: 5

D: 9

Which one is NOT divisible? and PLEASE explain your answer!! I really need to know how to know this stuff!!

Here are my questions:

- Which # is NOT divisble by 843,720? (Explain your answer!)

- HOW do I find out if a number is divisible or NOT to another number? (What do I do? Explain It To Me Please! I NEED to know this in the future!!)

Answer Both my questions in ORDER please and whoever does that is who Ill choose as best answer! :)

- Dont worry this question is NOT for homework, honest! Oh and be honest please lol. Thank you. Have a good night. Bye. ♥

Answer 1

X is divisible by Y if X/Y = an integer.

some examples:

10 is divisible by 5, 10/5 = 2

10 is divisible by 2, 10/2 = 5

33 is divisible by 11, 33/11 = 3

anything is divisible by 1

3 is not divisible by 2, 3/2 = 1.5

9 is not divisible by 7, 9/7 = 1.285714...

5 is not divisible by 3, 5/3 = 1.6666666666...

Answer 2

just divide 843720 by all the numbers in a calculator and whichever one comes out to a decimal answer is the one that it isnt divisible by

Answer 3

A. all even numbers are divisible by 2.

B. a number is divisible by 3 if you add all the digits together and the answer is divisible by 3. 843,720 : add the digits together and get 24. Add them again and you get 6. Six is divisible by 3.

C. Numbers ending in 5 and 0 are divisible by 5.

D. This is similar to 3, but instead of adding up to a multiple of 3, it must add to a multiple of 9.

The answer, therefore, is D.

Answer 4

A: Yes, it is divisible by 2 because the last digit is 0, 2, 4, 6, or 8.

B: Yes, it is divisible by 3 because the sum of the digits is 24, which is divisible by 3, therefore the number itself is also divisible by 3.

C: Yes, it is divisible by 5 because the last digit is 0 or 5.

D: No, it is not divisible by 9 because the sum of the digits is 24, which is not divisible by 9, therefore the number itself is also not divisible by 9.

Answer 5

you can automatically count out answers A and C because the last digit is a 0 (even number), so that leaves us with B and D.

split the number up to make it smaller and easier to work with.

Ex. 843,000+720= 843,720

Let's start with 720 since it is smaller.

600+120=720

3 goes into 600 and 120, so half of the problem works.

600,000+243,000=843,000

3 goes into 600,000.

243,000 is still to big for mental calculations

240,000+3,000=243,000

3 goes into 240,000 and 243,000.

3 works for 843,720, so that leaves 9 as the only answer that does not work.

Just cut the numbers up into easy number pieces, but be sure to check if the last digit is even or not first!

Hope this helps.

Answer 6

2+2=4