For the first box, you'll type in "100,000" without quotes. Chances are you will also erase the comma as well. Don't erase the comma until you are certain that there are 5 zeros present. To be sure if you have a comma or not, it might be best to ask the teacher for clarification.
We multiply 2.56 times 100,000 to get 256,000
To write 100,000 as a power of 10, we write it as 10^5
In other words, 10^5 = 100,000
Therefore, 5 goes in the second box
Notice how to get from 2.56 to 256,000 we move the decimal point 5 spots to the right. The exponent 5 over the 10 tells us how far to move. The positive exponent means "Move to the right"
So to summarize
[tex]256,000 = 2.56 \times {\bf{100,000}} = 2.56 \times 10^{\bf{5}}[/tex]