Trying to use an external number pad

I purchased a external number keypad to use with my MacBook. On the back of the keypad it does not list the model of the keypad. All it says on the back is a sticker that says Model: USB port. It also mentions on the back that it is Mac compatible. When I plug in the keypad to my Mac, when I try to use it in Numbers or Pages, whenever I try to press a number, it does a quick "double beep" for every button I press. The numbers, do type out on the screen, but there is the double beep sound that does not go away. I can turn off the sound when I am trying to work, sure, but what if I want to listen to music at the same time? Also, when I try to use the number pad in the calculator app the numbers do not print. When I try to use the number pad in say the address bar in Safari, there are no beeps. Any suggestions on what I may be able to do?