For your UITextfield use this in code:
myTextField.keyboardType=UIKeyboardTypeDecimalPad;
In iOS 5.1 or 6.1 iPad only these keyboard are available:
- UIKeyboardTypeASCIICapable
- UIKeyboardTypeNumbersAndPunctuation
- UIKeyboardTypeURL
- UIKeyboardTypeNumberPad
- UIKeyboardTypeNamePhonePad
- UIKeyboardTypeEmailAddress
- UIKeyboardTypeTwitter