16 Key Keypad

Keyboards that have keys: 0-F

Querty Mapping Convention

$$\left[\begin{array}{cccc}& & & \\ 1& 2& 3& C\\ 4& 5& 6& D\\ 7& 8& 9& E\\ A& 0& B& F\end{array}\right]\to \left[\begin{array}{cccc}1& 2& 3& 4\\ Q& W& E& R\\ A& S& D& F\\ Z& X& C& V\end{array}\right]$$