Monday, February 8, 2010

Divisibility

Divisible - When a number can be divided by another number, with no remainder.
Divisibility Rules - Quick ways to determine if a number is divisible by another number.


Rule for 2 - All even numbers are divisible by 2.
- Any number ending in 0,2,4,6,8
eg.
- 4 is divisible by 2
- 280 is divisible by 2
- 2971 is not divisible by 2

Rule for 5 - Any number that ends in 5 or 0.
eg.
- 155 divisible by 5
- 8974 is not divisible by 5

Rule for 10 - Any number that ends in 0.
eg.
- 1070 is divisible by 10
- 27367 is not divisible by 10
- 360.4 is not divisible by 10
- 364.0 is not divisible by 10

Quotient - Is the result of a division question.
eg.
- 12 divided by 2 = 6. Quotient is 6

Rule for 4 - Look at the last 2 digits, are they divisible by 2 twice?
eg.

The rule for 4 - If the last 2 digits are divisible by 2 twice, then the number is divisible by 4.

Rule for 8 - If the last 2 digits are divisible by 2 three times, then the number is divisible by 8.
eg.
16 divided by 2 = 8 8 divided by 2 = 4 4 divided by 2 = 2 = yes
18 divided by 2 = 9 9 divided by 2 = 4.5 = no
17948 = 48 divided by 2 = 24 24 divided by 2 = 12 12 divided by 2 = 6 = yes

Rule for 7 - Use calculator. There is no short-cut yet! You should find one and name it after yourself.

Rule for 3 - Add up all the digits until you have a single digit remaining. If that digit is divisible by 3 the number is divisible by 3.
eg.
93 = 9+3 =12 1+2=3 =
yes
273 = 2+7+3=12 1+2+3 = yes
1045 = 1+0+4+5=10 1+0=1 =
no

Rule for 6 - Any number that is divisible by 2 and 3.

Rule for 9 - Add up all the digits until you have 1 digit. If that digit is 9 the number is divisible by 9.
eg.
18 = 1+8=9 = yes
54 = 5+4=9 = yes
468 = 4+6+8=18 1+8=9 = yes
2345 = 2+3+4+5=14 1+4=5 = no

Rule for 0 - Nothing is divisible by 0.

*If you guys still have problems with Divisibility click on this website* =
http://math.about.com/library/bldivide.htm

Enjoy the video :D


24 comments:

  1. Nice post Raelynn!!! It was very organized and easy to read. Next time you shouldn't use so many colours but other than that great job!!!

    ReplyDelete
  2. Nice post Raelynn. It looks very neat and organized. Next time make your link into a word. Other than that great job.

    ReplyDelete
  3. Great post Raelynn, I like how everything is organized! but next time try to not use so many colours, Besides that Great job!

    ReplyDelete
  4. Good Job Raelynn! Your scribe looks fantastic! It's very organized, understandable and neat. I liked how you used different colours for some words and nice video by the way.

    ReplyDelete
  5. Great post Raelynn! Your scribe is very neat and organize but i would like it to make your font a little bigger.But your video was good and everything else is seems to fine.Good job!

    ReplyDelete
  6. Great post Raelynn! I like how it's organized. Next time, make your link into a word.

    ReplyDelete
  7. Great job raelynn! The video was nice and you should put the link in a word other than that great job

    ReplyDelete
  8. Nice post raelynn it was really neat and organized but next time you do it again try to put the link into a word if you don't remember go back to the very first blog that mark did but everything else was great.

    ReplyDelete
  9. Great post Raelynn. I like that your scribe is nice and neat. I also like how you changed the colour of the important words. Next time you should make the link into a word.

    ReplyDelete
  10. good job Raelynn. I like how you used different colours to stand out. But you should have put the link in a word.

    ReplyDelete
  11. Great job, Raelynn! I liked the different colors of the font so it can stand out, but next time you should put the link in a word. Other than that, you did an awesome job!

    ReplyDelete
  12. Good post. You did a great job. I like the way you changed the font of some words. Great job.

    ReplyDelete
  13. Good job. Next time put a link in. I really liked the colours.

    ReplyDelete
  14. Nice job, Realynn. I really liked how you changed the color of some important words. I also liked the video, picture and link you posted. Next time, try to put the link into a word.

    ReplyDelete
  15. Very nice post Realynn. I thought that all of the colors made the post very nice looking. But next time try to put the link on a word.

    ReplyDelete
  16. nice post Raelynn.i like the video that you posted but mext time you should put the link on a word

    ReplyDelete
  17. Nice post Raelynn. I liked how you changed the font colors and the video helped me.

    ReplyDelete
  18. Nice post Raelynn! I really liked the video,it really helped me.Next time you should put the link as a word.Very nice job!

    ReplyDelete
  19. Good job realynn! Good link but maybe next time put the link as a word!

    ReplyDelete
  20. Good post Raelynn. I really liked how you made a lot of the words stand out !

    ReplyDelete
  21. Good post i really liked it. the video helped me.

    ReplyDelete
  22. GOod post, but i think u should put the link as words, other than that nice job

    ReplyDelete
  23. Nice Post Raelynn, I liked how you made some of the important words stand out!

    ReplyDelete
  24. Nice post but the font was a little small!

    ReplyDelete