64
32,2
16,2,2
8,2,2,2
4,2,2,2,2
2,2,2,2,2,2
100 50,2 25,2,2 5,5,2,2
120 60,2 30,2,2 15,2,2,2 5,3,2,2,2
It looks like an upside-down tree - which is how it gets its name.
Since 5 is a prime, it looks like the end of a branch.
A Factor tree looks like this:... 42... / . \..2 ...21....... / . \.......3 . 7So the prime factors of 42 are 2 x 3 x 7
A Factor tree looks like this: ... 42 ... / . \ ..2 ...21 ....... / . \ .......3 . 7 So the prime factors of 42 are 2 x 3 x 7
Since 61 is already prime, a factor tree is not necessary. The prime factorization of 51 is 3 x 17, which wouldn't make much of a tree. More like a factor shrub.
50 25,2 5,5,2
18 9,2 3,3,2
10 2,5
The purpose of a factor tree is to notate the process of finding the prime factorization. If a number is already prime, a factor tree is not necessary.
The purpose of a factor tree is to divide a number into prime factors. 1 is not a prime number.