The objective of my project is that the 4-bit counter which has a range of 0-9, counts to the desired binary number using outside dip switches then returns to the beginning again. This is what I have come up with so far but I am a bit puzzled. How can I implement the dip switches into the circuit, also how can make it count back to zero after displaying the desired number?

Apiping systems consists of 6 m of 6-std type k and 12 m of 4-std type k, both drawn copper tubing. the system conveys ethylene glycol at a rate of 0.013 m3/s. the pressure drop across the system is to be calculated. there are two 90° elbows in the 6-in pipe, a reduction from the 6-in pipe to the 4-in pipe and four 90° elbows in the 4-in pipe. all fittings are soldered (same as flanged) and regular. the inlet and outlet of the system are at the same height.