or already know off the top of your head just which key combination enables and disables the use of your keyboard as a numerical key pad. That is probably what happened.
If that doesn't work don't know what else to tell you because you didn't think it important enough to tell us the make and specific model of your laptop as well as the OS and version and all laptops and operating systems are not the same.
My cat walked across my laptop (before i could stop her) now none of my computer keys work. I switched my computer off and restarted it, but I can't even type my password in. Help....what do I do???