Prime and Composite Numbers

TASK

Click the [b]Pen[/b] tool, choose [i]Select Object,[/i] and double-click the table to edit it. Complete the table and take note of your observations.

Question 1

Which of the following numbers has the most number of factorizations?

11 10 9 12

Question 2

Which of the following numbers has only two factors?

2 10 9 7

Question 3

What do you think is the smallest number of factors of any number? Why?

Discussion

Numbers that have only two factors are called[b] [color=#0000ff]prime numbers[/color][/b]. For example, 11 is a prime number because its only factors are 1 and 11. Numbers with more than two factors are called [color=#0000ff][b]composite[/b] [b]numbers[/b][/color]. For example, 6 is a composite number because its factors are 1, 2, 3, and 6.[br][br]The number 1 is a special number. It is not composite and it is not prime.

Question 4

Which of the following are prime numbers?

3 4 2 5

Question 5

Which of the following are composite numbers?

9 7 8 10

Question 6

If we think of prime and composite numbers as areas of rectangles formed by unit squares, which of the following is true about them?

You can form [b]more than one rectangle [/b]if the number is [b]prime[/b] You can form [b]more than one rectangle[/b] if the number is [b]composite[/b]. You can only form[b] one rectangle[/b] if the number is [b]composite[/b]. You can only form [b]one rectangle[/b] if the number is [b]prime[/b].