Fujitsu laptop keyboard showing wrong characters

Whenever I press certain letters I get a numeric stroke. For example:
 
m=0
j=1
k=2
l=3
u=4
i=5
o=6
 
Solution :
 
Try to find a key on your keyboard labeled “Num Lock” and press it (you may have to hold down something like an “Fn” key while pushing the Num Lock button).

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