Difficult understanding simple calculator

Question

Good day guys,

I tried running the simple calculator but it gave me an error. I also don't understand "user_input: user(":")"

Answer 1

you should enter as many inputs as there are in the code:
exemple code:
a=input("1st Num")
b=input("2nd Num")

>>>Run
when the program asks you for a number put both numbers as follow
3
5
then press enter