+ 5.3a prime & composite kim norman ges 2014 + eratosthene of cyrene born: 276 bc in cyrene,...
TRANSCRIPT
+
5.3aPrime & Composite
Kim NormanGES2014
+Eratosthene of Cyrene
Born: 276 BC in Cyrene, North Africa (now Shahat, Libia)
Died: 194 BC in Alexandria, Egypt
+ Sieve of Eratosthenes
+Sieve of Eratosthenes
Since 1 is not prime, color it purple
+Sieve of Eratosthenes
Circle the 1st prime number, 2 with your pencilColor every multiple of 2 on your chart
yellow
+Sieve of Eratosthenes
Circle the next prime number, 3 with your pencilColor the multiple of 3 on your chart
red (some multiples of 3, such as 6 and 12, may already be colored yellow. Ignore these and look for the uncolored multiples16
+Sieve of Eratosthenes
Circle the next prime number, 5. Color any uncolored multiples of 5
blue. 6
+Sieve of Eratosthenes
Circle the next prime number, 7.Color any uncolored multiples of 7
green.3
+Sieve of Eratosthenes
Count the uncolored squares on your chartCan you find 25 of them?
If you can, then you have sifted out all of the prime numbers under 100
+Primes & Composites
BrainPopNumbers & Operations
Prime Numbers
+What are Prime Numbers?
?
+What are Prime Numbers?
DefinitionA whole number with exactly two
factors, 1 and itself
+What are Prime Numbers?
CharacteristicsWhole numberOnly has 2 factors
1 and itself
+What are Prime Numbers?
Examples2, 3, 5, 7, 11…
Example: 2 is a prime number2 x 1 (only 2 factors)
Example: 13 is a prime number13 x 1 (only 2 factors)
+What are Prime Numbers?
Non-Examples0, 1, 4, 6, 8, 9…
+Is 1 a Prime Numbers?
How many factors does the number 1 have?Answer = 1
A Prime Number has to have 2 factors So, the number 1 cannot be a Prime Number
+What are Composite Numbers?
?
+What are Composite Numbers?
DefinitionA whole number that has more than
two factors
+What are Composite Numbers?
CharacteristicsWhole numberHas more than 2 factors
+What are Composite Numbers?
Examples 4, 6, 8, 9, 10…
Example: 4 is a composite number1 x 42 x 2(4 has more than 2 factors, it has 3 factors)
Example: 12 is a composite number1 x 122 x 63 x 4(12 has more than 2 factors, it has 6 factors)
+What are Composite Numbers?
Non-Examples0, 1, 2, 3, 5, 7…
+Is 1 a Composite Numbers?
How many factors does the number 1 have?Answer = 1
A Composite Number has to have more than 2 factors So, the number 1 cannot be a Composite
Number
+So 1 is…
Neither Prime
Nor Composite
+Prime, Composite, or Neither…
6
9
7
1
3
5
2
4
10
8
+Prime, Composite, or Neither…
21
60
25
100
32
29
1
81
72
37
+ Finding Prime & Composite
Lets use Connecting Color Tiles
+Rectangles Chart
Number Factors Number of Rectangles
Prime or Composite
1
2
3
4
5
6
7
8
+1 = Neither Prime (only 2 factors)
Nor Composite (more than 2 factors)
1 only has one factor
+2 = Prime
1 x 2 (2 factors)
+3 = Prime
1 x 3 (2 factors)
+4 = Composite
(3 factors)
1 x 4
2 x 2
+5 = Prime
1 x 5 (2 factors)
+6 = Composite
(4 factors)
1 x 6
2 x 3
+7 = Prime
1 x 7 (2 factors)
+8 = Composite
(4 factors)
1 x 8
2 x 4
+
Can You Tell the Difference Between Prime & Composite Numbers?
http://www.321know.com/fra63ax2.htm
+XPMath Primes vs. Composites
XPMath Primes vs. Composites
Monkey Drive
Fruit Splat
King Kong's Prime Numbers
Prime or Composite?
+
Now it’s time for the… Prime and Composite Quiz
Any questions?
Are your ready?
Great, let’s get on IA iTest and get started…
SOL5.3aQuiz