# 4D Primes, Composite numbers

Good morning!
Schedule:
• Learning goals
• What did we do wednesday
• Prime and composite numbers
• Prime factorization
• Worksheet
1 / 16
Slide 1: Tekstslide
WiskundeMiddelbare schoolvwoLeerjaar 4

In deze les zitten 16 slides, met interactieve quizzen en tekstslides.

## Onderdelen in deze les

Good morning!
Schedule:
• Learning goals
• What did we do wednesday
• Prime and composite numbers
• Prime factorization
• Worksheet

#### Slide 1 -Tekstslide

Learning goals
At the end of this lessons I can:
• Define a numbers as a prime or a composite number
• Find the prime factorization of any (whole) number

#### Slide 2 -Tekstslide

What did we do last time?

#### Slide 3 -Woordweb

What is HCF(13, 5)?

#### Slide 4 -Open vraag

4D: Primes and composite numbers
HCF(13, 5) = 1
because 13 and 5 are both Prime numbers

Factors of 13:

Factors of 5:

#### Slide 5 -Tekstslide

4D: Primes and composite numbers
A prime number is a natural number with only 2 factors
Ex.  The factors of 7 are 1 and 7

#### Slide 6 -Tekstslide

4D: Primes and composite numbers
A prime number is a natural number with only 2 factors
A composite number is a natural number with more than 2 factors
Ex.  The factors of 7 are 1 and 7
Ex.  The factors of 10 are 1, 10, 2, 5

#### Slide 7 -Tekstslide

4D: Prime factorization
Every Composite number can be written as the product of prime numbers factors

6
= 2 3

15 = 3 5

#### Slide 8 -Tekstslide

4D: Prime factorization
With larger numbers we can use 2 strategies:
Repeated division

or

Factor tree

#### Slide 9 -Tekstslide

Repeated division

180
Factor tree

180
Write along!

#### Slide 10 -Tekstslide

4D: Prime factorization
Repeated division or Factor tree?

Use what works best for you!!

#### Slide 11 -Tekstslide

Homework
4D            2, 6efgh, 7behk, 8

MyiMaths

#### Slide 12 -Tekstslide

4D: Primes and composite numbers
Step 1: Is 1 a prime number?

#### Slide 13 -Tekstslide

4D: Primes and composite numbers
Step 1: Is 1 a prime number?
Step 2: Is the next number a prime number?
Yes            Circle it
No             Cross it off

#### Slide 14 -Tekstslide

4D: Primes and composite numbers
Step 1: Is 1 a prime number?
Step 2: Is the next number a prime number?
Yes            Circle it
No             Cross it off
Step 3: Cross off any number that is divisible by the number from step 2

#### Slide 15 -Tekstslide

4D: Primes and composite numbers
Step 1: Is 1 a prime number?
Step 2: Is the next number a prime number?
Yes            Circle it
No             Cross it off
Step 3: Cross off any number that is divisible by the number from step 2
Step 4: Repeat step 2 and 3