NumberPickers before API 11
As you may know, Android has a NumberPicker but this NumberPicker is only available for API 11 (HoneyComb) or newer. The workaround for using a number picker is to implement your own Widget Library.
Here is a list of Widget Libraries that you should use:
SimonVT’s NumberPicker(Personally Used): https://github.com/SimonVT/android-numberpicker
Michael Novak’s NumberPicker (He also has a demo and a guide on his website): https://github.com/mrn/numberpicker
These two come highly recommended:
Android Wheel: http://code.google.com/p/android-wheel/
Horizontal slider widget: http://blog.sephiroth.it/2012/01/28/android-wheel-widget/
Once you include these files into your project; you can implement the NumberPicker like any regular widget in xml files or dynamically.