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##### Prime and Composite Numbers

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 hvlawson Joined: Jul 2008 Posts: 108 Full Member
hvlawson

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Prime and Composite Numbers
08-04-2010, 09:52 AM
 #1

Do you all have anything to share on prime and composite numbers?

 poppyrocky Joined: Jun 2010 Posts: 93 Full Member
poppyrocky

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08-04-2010, 10:15 AM
 #2

these to post up in my room. (Just a quick definition of prime and composite) I'll post the page I have devoted to the number 1 in the next post.

Nothing too fancy.
Attached Files
 prime and composite.doc (27.0 KB, 369 views)

 poppyrocky Joined: Jun 2010 Posts: 93 Full Member
poppyrocky

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2nd Part
08-04-2010, 10:16 AM
 #3

Can't leave 1 out!
Attached Files
 1 poster.doc (650.0 KB, 265 views)

 imcrazedw4 Joined: Jun 2010 Posts: 617 Senior Member
imcrazedw4

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08-04-2010, 10:27 AM
 #4

I gave my students a hundreds chart and had them highlight the prime numbers. I then had them put that chart in a plastic sleeve and put it in their 1-1/2 inch 3-ring math binder to use as a reference. It worked out very well.

 Firebelly Joined: Jan 2009 Posts: 793 Senior Member
Firebelly

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Here's a cool thing...
08-04-2010, 01:59 PM
 #5

Write out the numbers 1-20 on a sheet of paper. Write them balloon style so students can color them in when given the direction to do so. Since 1 is not prime or composite, it doesn't get colored in at all.
Two is prime so the whole number two gets colored in (red).
Three is prime, but different than two, so gets colored in a different color (green).
Four is composite. Draw a line dividing the number in half horizontally. Since its factors are two and two, draw the upper half red as well as the lower half.
Five is prime, but different than two and three, so gets colored in a different color (blue).
Six is composite. Draw a line dividing the number in half horizontally. Since its factors are two and three, the upper half is colored red and the lower half is colored green.
Seven is prime and needs to be a different color than what has been used so far (yellow).
Eight is composite. Draw a line dividing the number in half horizontally. The upper half will represent the 2 in 2 x 4 and will be colored red. The lower half represents 4, so draw a line dividing the lower half in half again and color both sides red as well. In this manner, you are also teaching prime factorization (2 x 2 x 2 =8)

Keep going in this manner, filling in the sheet. At the end, students can visually see the prime numbers (solid colors) versus the composite numbers (multicolored or divided into smaller parts).

If this is not clear to you, let me know. I have an example at school and could post a copy.

 StephR Joined: Aug 2005 Posts: 1,893 Senior Member
StephR

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08-04-2010, 03:36 PM
 #6

We review prime and composite numbers daily during Calendar. The first thing we do, it list all of the arrays for a number. Then, from those arrays, we list the factors. Using hand motions (since I want to get them all actively involved during Calendar), they tell me if it is prime or composite. We say the following:

Prime numbers have 2 factors and 2 arrays. (showing two piece signs on our fingers and shaking them)
Composite numbers have more than 2 factors and more than 2 arrays. (making a "bursting" motion into a rainbow...that is a weird description of it..sorry!)

Since they can visually see the arrays and factors daily, recognizing prime and composite numbers becomes second nature.

 hvlawson Joined: Jul 2008 Posts: 108 Full Member
hvlawson

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08-04-2010, 06:14 PM
 #7

Thank you all so much!

 calicocookie Joined: Jul 2010 Posts: 163 Full Member

Joined: Jul 2010
Posts: 163
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Thank you
08-05-2010, 02:59 AM
 #8

for the posters but is the #1 poster supposed to say it is not composite on the bottom. The word composite doesn't show up.

 becky2624 Joined: Jul 2006 Posts: 268 Full Member
becky2624

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Six Pack
08-05-2010, 08:54 AM
 #9

I do a lot of the activities mentioned, but I also have the students memorize the "Six Pack." They draw a rectangle with six compartments and put the numbers 2, 3, 5, 7, 11, 13 inside. It's a good visual and it helps job their memories about what prime numbers are.

 poppyrocky Joined: Jun 2010 Posts: 93 Full Member
poppyrocky

Joined: Jun 2010
Posts: 93
Full Member
#1 poster....
08-05-2010, 12:02 PM
 #10

I used a special font I downloaded, so that probably changed the formatting.

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