ANother stoopid question bout laptops

[Tippychick]

my 2yo has pressed something that means the keys have reverted to what is printed on their underneaths. so o is 6 unless i hold down a key that says fn when i type. hooooooow do i reverse that????

Num Lock perhaps

Thanks so much. I am so thick when it comes to laptops, they confuse me greatly. Thanks for helping!