© t madas. what is a prime number? a prime number is a number with exactly 2 factors the 2 factors...
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© T Madas
© T Madas
What is a prime number?
A prime number is a number with exactly 2 factors
The 2 factors of any prime number are:• number 1• the prime number itself
2, 3, 5, 7, 11, 13, 17,19, 23, 29, 31, 37, 41,…
1 is not a prime number
© T Madas
24
2 12
2 6
2 3
= 2 x 2 x 2 x 3 = 23 x 31
3 1
Every number can be written as a product of prime numbers [and number 1]
FACT:
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30
2 15
3 5
5 1
= 2 x 3 x 5 = 21 x 31 x 51
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36
2 18
2 9
3 3
3 1
= 2 x 2 x 3 x 3= 22 x 32
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48
2 24
2 12
2 6
2 3
3 1
= 2 x 2 x 2 x 2 x 3= 24 x 31
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60
2 30
2 15
3 5
5 1
= 2 x 2 x 3 x 5 = 22 x 31 x 51
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72
2 36
2 18
2 9
3 3
= 2 x 2 x 2 x 3 x 3 = 23 x 32
3 1
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120
2 60
2 30
2 15
3 5
5 1
= 2 x 2 x 2 x 3 x 5 = 23 x 31 x 51
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168
2 84
2 42
2 21
3 7
7 1
= 2 x 2 x 2 x 3 x 7= 23 x 31 x 71
With bigger numbers use a calculator
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540
2 270
2 135
3 45
3 15
= 2 x 2 x 3 x 3 x 3 x 5= 23 x 32 x 51
3 5
5 1
With bigger numbers use a calculator
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Decompose these numbers into their prime factors.Write the final answer using powers
•20
•30
•36
•45
•60
•72
•90
•144
•150
•196
•288
•360
© T Madas
© T Madas
12
26
23
31
12 =2 x 2 x 3
12 =22 x 3
Write these numbers as a product of prime factors
18
29
33
31
18 =2x 32
24
212
2 6
2 3
24 =2 x 2 x 2
31
x 3
24 =23x 3
18 =2 x 3 x 3
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20
210
25
51
20 =2 x 2 x 5
20 =22 x 5
Write these numbers as a product of prime factors
30
215
35
51
30 =2 x 3 x 5
36
218
2 9
3 3
36 =2 x 2 x 3
31
x 3
36 =22x 32
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45
59
33
31
45 =3 x 3 x 5
45 =32 x 5
60
230
215
35
60 =2 x 2 x 3
72
236
218
29
72 =2 x 2 x 2
33
x 3
72 =23x 32
51
x 5
60 =22 x 3 x 5
31
x 3
Write these numbers as a product of prime factors
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48
224
212
26
48 =2x 2x 2
48 =24 x 3
Write these numbers as a product of prime factors
23
31
x 2 x 3
54
227
39
33
54 =2 x 3 x 3
31
x 3
54 =2x 33
56
228
214
27
56 =2 x 2 x 2
71
x 7
56 =23x 7
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84
242
221
37
84 =2x 2x 3
84 =22 x 3
Write these numbers as a product of prime factors
71
x 7
90
245
59
33
90 =2 x 3 x 3
31
x 5
90 =2x 32x 7 x 5
80
240
220
210
80 =2 x 2 x 2
25
x 2
80 =24x 5
51
x 5
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100
250
225
55
100 =2x 2x 5
100 =22x 52
Write these numbers as a product of prime factors
51
x 5
210
2105
521
37
210 =2 x 3 x 5
71
x 7
108
254
227
39
108 =2 x 2 x 3
33
x 3
108 =22x 33
31
x 3
© T Madas
© T Madas
12
26
23
31
12 =2 x 2 x 3
12 =22 x 3
Write these numbers as a product of prime factors
18
29
33
31
24
212
2 6
2 3
24 =2 x 2 x 2
31
x 3
24 =23x 318 =2x 32
18 =2 x 3 x 3
© T Madas
20
210
25
51
20 =2 x 2 x 5
20 =22 x 5
Write these numbers as a product of prime factors
30
215
35
51
30 =2 x 3 x 5
36
218
2 9
3 3
36 =2 x 2 x 3
31
x 3
36 =22x 32
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45
59
33
31
45 =3 x 3 x 5
45 =32 x 5
60
230
215
35
60 =2 x 2 x 3
72
236
218
29
72 =2 x 2 x 2
33
x 3
72 =23x 32
51
x 5
60 =22 x 3 x 5
31
x 3
Write these numbers as a product of prime factors
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48
224
212
26
48 =2x 2x 2
48 =24 x 3
Write these numbers as a product of prime factors
23
31
x 2 x 3
54
227
39
33
54 =2 x 3 x 3
31
x 3
54 =2x 33
56
228
214
27
56 =2 x 2 x 2
71
x 7
56 =23x 7
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84
242
221
37
84 =2x 2x 3
84 =22 x 3
Write these numbers as a product of prime factors
71
x 7
90
245
59
33
90 =2 x 3 x 3
31
x 5
90 =2x 32x 7 x 5
80
240
220
210
80 =2 x 2 x 2
25
x 2
80 =24x 5
51
x 5
© T Madas
100
250
225
55
100 =2x 2x 5
100 =22x 52
Write these numbers as a product of prime factors
51
x 5
210
2105
521
37
210 =2 x 3 x 5
71
x 7
108
254
227
39
108 =2 x 2 x 3
33
x 3
108 =22x 33
31
x 3
© T Madas