How do you zoom the screen in and out.
If you're referring to the home screen itself, unfortunately it can't be done. The closest thing to it that you can do is by adjusting the font size under the Settings. Choose the largest font setting available and you'll be good to go. Also, if you're talking about zooming in on pictures and possibly even videos, try pinching the screen at the point which you want to zoom in/out to. Pinch out to zoom in, pinch in to zoom out.