If you have a number keypad on the right side of your keyboard, but it's not typing numbers on your remote workstation, it is likely the result of the Windows Num-Lock function.
The first time you connect to a workstation, the number pad on your keyboard defaults to functioning as directional arrow keys. To change their function to number keys, press the key above the 7 key in the number bank. On a Mac keyboard, this is the clear key, and on PC keyboards, it is the num-lock.