How to scroll in a text field

There are times when I need to enter text in a text block or "field" and it is longer than the text block will hold. Iff I make a mistake at the begining, I can't find a way to scroll to the left side of the field. I end up deleting it and reentering the entire entry. A good example is Maps. It won't let you go to landscape mode to get more room and when you enter a destination that includes street address, city, state, it can get pretty long.

Thanks. Brad.