Numeral lock

[beltbyron]

some letters tpe numbers,ie, (m-0)(u-4),and i dont know how to switch it back

 

[frozenlead]

Are there small blue numbers on those keys below or near the white letters that actually say what the keys are?

If so, you're probably using a Fn numberpad. You have some sort of Function lock enabled. Search for something of the sort on your keyboard or in your manual.