#include<iostream>//We start by placing the libraries
using namespace std;//We start by placing the libraries
int main(){//main function
intnumbers;
cout<<"1-summation"<<endl<<"2-differentiation"<<endl<<"3-multiplication"<<endl<<"4-division"< <endl;
cout<<"enter the number to operate";
cin>>numbers;
if (numbers>=1 &&numbers<=4){
inta,b;// if But we will only be able to call variables inside an if statement. We can define variables inside a statement 
cout<<"Please put the first number you want to operate";
cin>>a;
cout<<"Please put the second number you want to operate";
cin>>b;
if (numbers==1)//If the process number1 Do the following
cout<<a<<"+"<<b<<"="<<a+b<<endl;
//And do the collecting a and b Print the two numbers in 
if (numbers==2)//If the process number2 Do the following
cout<<a<<"-"<<b<<"="<<a-b<<endl;
//And do the subtraction a and b Print the two numbers in 
if (numbers==3)//If the process number3 Do the following
cout<<a<<"*"<<b<<"="<<a*b<<endl;
//And do the multiplication a and b Print the two numbers in 
if (numbers==4)//If the process number4 Do the following
cout<<a<<"/"<<b<<"="<<a/b<<endl;}
//And do the division a and b Print the two numbers in 
else{cout<<"Are you serious, I told you its from 1 to 4"<<endl;}
//Other than that If the condition is not met, print that the number is invalid
return 0;
}