all prime factors of900

Prime numbers are:  2, 3, 5, 7, 11, ...

Start with 2:  900 ÷ 2  =  450

                    450 ÷ 2  =  225

                    225 ÷ 2  =  a fraction; so, don't count this

Next, try 3:  225 ÷ 3  =  75

                     75 ÷ 3  =  25

                     25 ÷ 3  =  a fraction; so, don't count this

Next, try 5:    25 ÷ 5  =  5

                      5 ÷ 5  =  1  We're done!

The prime factors are 2, 3, and 5.

The prime fractorization is:  2² · 3² · 5²   (the prime factors with the number of times each one is used)