Insertion sort "by hand" 

Input:   3   2   5    1    12    9    8    5    7

Step 1:  3

Step 2:      3
         2   3


Step 3:  2   3   
         2   3   5


Step 4:      2   3   5
         1   2   3   5


Step 5:  1   2   3   5
         1   2   3   5   12

Step 6:  1   2   3   5        12
         1   2   3   5    9   12

Step 7:  1   2   3   5         9   12
         1   2   3   5    8    9   12

Step 8:  1   2   3        5    8    9   12
         1   2   3   5    5    8    9   12

Step 9:  1   2   3   5    5         8    9   12
         1   2   3   5    5    7    8    9   12