I just read that the number row is a premium feature. They let you use those features free but if you buy the premium version it won't reset hourly. I guess that's how they let you demo the feature and annoy you into the upgrade. It's worth it IMO.
I have the Google Keyboard with the language option set to English UK PC. This gives a qwerty keyboard with the appearance of a PC layout, ie. numbers at the top. It works well on a gs4.