|Which number keys ?|
The ones all in one row at the top of the keyboard, or the ones in the number pad on the right?
The ones in number pad - the Num Lock led must be on - pressing the Num Lock key toggles it on / off.
When the Num Lock led is off, the 0 - 9 and period keys are for the other functions printed on the keys.
If that doesn't help, tell us your laptop brand name model.