Answer 1

2
3
+
Submit

u did
2+3
Submit

Answer 2

num1=int(input("Enter the first number:"))
num2=int(input("Enter the second number"))
op=input("Enter an operator : ")

According to your code.,. You should first input the two numbers and then the operator... Like..
2
5
+

Answer 3

What corrections you want?
is there any error you getting?

Answer 4

In enter popup enter
4 <enter>
5 <enter>
+<submit>