When you edit the contents of a cell, pressing the cursor keys brings in cell numbers. How do you get it to NOT do that?

Someday I will look for (learn how to use) a better calculator. In the meantime, I get by by using Google spreadsheets. My latest difficulty / annoyance was that I couldn't use the cursors keys inside of a cell. I write a formula, and the first time I write it it is usually wrong, so I want to correct it, which means moving the cursor to the place where I need to delete a number of insert a paranthese, but it doesn't work. I press the left arrow key and it inserts some cell address. "I don't want that" I scream at the stupid machine but it doesn't care, shoot, it doesn't even acknowledge me. Uppity gizmo. So I pull up the help page and I explain my problem (which is where I got the title for this post), and low and behold, I found an answer. I am shocked. 

<< IF the LEFT ARROW KEY etc >>

Without saying what is the right or wrong way of doing things, the behaviour you have described is pretty much exactly the same as other spreadsheet applications (including the old version of GSheets, along with by far the most popular desktop one).  In other words, there are two distinct "modes" of editing in-cell:

1. When you type a new entry in a cell, the arrow keys will not move the cursor within the cell, but rather move to a new cell.  However, if you reposition the cursor with the mouse within the cell, you will then be able to move the cursor with the left & right arrow keys.

2. When you go back to the cell in edit mode (not even considering the formula bar), w\you again by default will be able to move the cursor with the left & right arrow keys.

 By A.P.L. on the Google Help Forum