Prime Numbers

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Would it be possible to get a copy of this presentation for my class? masalas@wuesd.org. Thank you

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I was hoping I could download this to use with my math class (I teach fifth and sixth grade teachers) prime numbers are so difficult to teach....Thanks

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Prime NumbersEratosthenes’ Sieve: 

Prime Numbers Eratosthenes’ Sieve By Monica Yuskaitis

Eratosthenes(ehr-uh-TAHS-thuh-neez): 

Eratosthenes (ehr-uh-TAHS-thuh-neez) Eratosthenes was the librarian at Alexandria, Egypt in 200 B.C. Note every book was a scroll.

Eratosthenes(ehr-uh-TAHS-thuh-neez): 

Eratosthenes (ehr-uh-TAHS-thuh-neez) Eratosthenes was a Greek mathematician, astronomer, and geographer. He invented a method for finding prime numbers that is still used today. This method is called Eratosthenes’ Sieve.

Eratosthenes’ Sieve: 

Eratosthenes’ Sieve A sieve has holes in it and is used to filter out the juice. Eratosthenes’s sieve filters out numbers to find the prime numbers.

Definition: 

Definition Factor – a number that is multiplied by another to give a product. 7 x 8 = 56 Factors

Definition: 

Definition Factor – a number that divides evenly into another. 56 ÷ 8 = 7 Factor

Definition: 

Definition Prime Number – a number that has only two factors, itself and 1. 7 7 is prime because the only numbers that will divide into it evenly are 1 and 7.

Hundreds Chart: 

Hundreds Chart On graph paper, make a chart of the numbers from 1 to 100, with 10 numbers in each row.

Slide9: 

Hundreds Chart

Slide10: 

1 – Cross out 1; it is not prime.

Hint For Next Step: 

Hint For Next Step Remember all numbers divisible by 2 are even numbers.

Slide12: 

2 – Leave 2; cross out multiples of 2

Hint For Next Step: 

Hint For Next Step To find multiples of 3, add the digits of a number; see if you can divide this number evenly by 3; then the number is a multiple of 3. 2 6 7 Total of digits = 15 3 divides evenly into 15 267 is a multiple of 3

Slide14: 

3– Leave 3; cross out multiples of 3

Slide15: 

To find the multiples of 5 look for numbers that end with the digit 0 and 5. Hint For the Next Step 385 is a multiple of 5 andamp; 890 is a multiple of 5 because the last digit ends with 0 or 5.

Slide16: 

4– Leave 5; cross out multiples of 5

Slide17: 

5– Leave 7; cross out multiples of 7

Slide18: 

6–Leave 11; cross out multiples of 11

Slide19: 

All the numbers left are prime

The Prime Numbers from 1 to 100 are as follows:: 

The Prime Numbers from 1 to 100 are as follows: 2,3,5,7,11,13,17,19, 23,31,37,41,43,47, 53,59,61,67,71,73, 79,83,89,97

Credits: 

Credits Clipart from 'Microsoft Clip Gallery' located on the Internet at http://cgl.microsoft.com/ clipgallerylive/default.asp