FACTORS AND MULTIPLES

PRIME NUMBERS/NOMBOR PERDANA

• A prime number is a whole number that can only be divided by itself and the number 1.

• The number 1 is not prime (it does not have two different factors).

• The first five prime numbers are 2, 3, 5, 7, 11.

• 2 the smallest prime number and it is the only even number which is a prime number.

CHARACTERISTICS OF PRIME NUMBERS

• A number that has only two divisors (the number itself and 1) is a prime number.

a) 13 ( 2 divisors, 13 & 1 is a prime number)

b) 51 (4 divisors 51, 17, 3, 1 is not a prime number)

IDENTIFYING PRIME NUMBERS

• Determining all prime numbers less than 50 1 2 3 4 5 6 7 8 9 1011 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 3031 32 33 34 35 36 37 38 39 4041 42 43 44 45 46 47 48 49 50

Sila buat mengikut peraturan/kaedah pada mukasurat seterusnya…

FIND OUT YOURSELVES…

• Kaedah mencari nombor perdana kurang daripada 50 – bulatkan nombor perdana, pangkah yang bukan nombor perdana..

a) Pangkah no. 1 kemudian bulatkan no. 2 dan seterusnya pangkah nombor-nombor gandaannya, seperti no. 4, 6, 8, 10, 12 & seterusnya hingga ke no. 50

b) Teruskan pada nombor yang belum dibulatkan atau dipangkah, dan ulang proses sehingga semua nombor selesai dipangkah atau dibulatkan.

KAEDAH – BUAT SECARA INDIVIDU…

Adakah anda mengikut kaedah yang telah

disarankan?

Sila semak jawapan anda di mukasurat

seterusnya (Pastikan anda menggunakan

PAPARAN ‘SLIDE SHOW’ untuk semak

aktiviti tadi…)

1 2 3 4 5 6 7 8 9 10

11 12 13 14 15 16 17 18 19 20

21 22 23 24 25 26 27 28 29 30

31 32 33 34 35 36 37 38 39 40

41 42 43 44 45 46 47 48 49 50

STEP BY STEP… SILA GUNA PAPARAN ‘SLIDE SHOW’ UNTUK SEMAK KAEDAH SECARA TERPERINCI… )

The prime number less than 50.

The prime numbers between 20 and 40

All the prime numbers that are greater than 35 but less than 50

LIST…

2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43 and 47

23, 29, 31 and 37

37, 41, 43 and 47

FACTORS

FACTORS AND MULTIPLES

A factor of a given whole number is a number that can be divided by that

number exactly

FACTOR

Find all the factors of the following numbers.

42

56 70

LISTING FACTORS OF WHOLE NUMBERS

(1, 2, 3, 6, 7, 14, 21, 42)

(1, 2, 4, 7, 8, 14, 28, 56)

(1, 2, 5, 7, 10, 14, 35, 70)

a) 8 is factors of 24b) 9 is factors of 106c) 14 is factors of 168d) 21 is factors of 283

DETERMINE WHETHER…

Yes

No

Yes

No

PRIME FACTORS/FAKTOR PERDANA

FACTORS AND MULTIPLES

Prime factors are prime numbers that are factors of the number"Prime Factorization" is finding which prime numbers you need to multiply together to get the original number.

PRIME FACTOR

• It is best to start working from the smallest prime number, which is 2, so let's check:• 12 ÷ 2 = 6• But 6 is not a prime number, so we need to factor it further:• 6 ÷ 2 = 3• And 3 is a prime number, so:• 12 = 2 × 2 × 3• As you can see, every factor is a prime number, so the answer must be right - the prime factorization of 12 is 2 × 2 × 3, which can also be written as 22 × 3.

WHAT ARE THE PRIME FACTORS OF 12?

63

156

210

147

330

LET’S DO PRIME FACTORIZATION..3 x 21 3 x 7 3 x 3 x 7 = 32 × 7

2 x 782 x 393 x 132 x 2 x 3 x 13 = 22 × 3 x 13

2 x 1053 x 355 x 72 x 3 x 5 x 7 = 2 × 3 x 5 x 7

3 x 497 x 7 3 x 7 x 7 = 3 × 72

3 x 552 x 165 5 x 112 x 2 x 3 x 13 = 22 × 3 x 13

•98•240•252•300•432•1650

MORE TO BE SOLVED…

2 x 7 x 7 = 2 x 72

2 x 2 x 2 x 2 x 3 x 5 = 24 x 3 x 5

2 x 2 x 3 x 3 x 7 = 22 x 32 x 7

2 x 2 x 3 x 5 x 5 = 22 x 3 x 52

2 x 2 x 2 x 2 x 3 x 3 x 3 = 24 x 33

2 x 3 x 5 x 5 x 11 = 2 x 3 x 52 x 11

Or you may use computer applications…

www.btinternet.com/~se16/js/prime.htm www.btinternet.com/~se16/js/factor.htm