Prime numbers

==lesson==
Making Factor Trees is good for factoring numbers, and finding their factors.
find a composite (not prime) number. For example, we will choose 24.
24
That is the Factor Tree so far.
OK, bare with me. Find the biggest factor (other than 24), and smallest factor (other than 1).
12 and 2.
-24
-/\
12 2
The tree was split into 2 parts. 2 is prime, so we circle 2.
--24
--/\
12 (2)
We will find the same factors, this time with 12. biggest is 6, and smallest is 2.
---24
---/\
-12 (2)
-/\
6--2
then again, 2 is prime, so circle it
---24
---/\
-12 (2)
-/\
6 (2)
OK, do the same with 6. It would be 3 and 2.
----24
----/\
--12 (2)
--/\
-6 (2)
-/\
3--2
Look, now we have 2 primes.
-----24
-----/\
---12 (2)
---/\
--6 (2)
--/\
(3)(2)
now that we can't find any more factors, we stop. That is our Factor Tree.
so to factor 24, we look at all the prime numbers. 3, 2, 2, 2.
So 24 = 3 x 2 x 2 x 2.
2 x 2 x 2 = 
So .
We factored 24!
Now to get the FACTORS themselves.
Look at all the numbers in the tree.
There is 24, 12, 6, 3 and 2. Those are the factors! (plus 1, of course)
The factors for 24 and 24, 12, 6, 3, 2 and 1.
24 factored is .
Category:Numbers