Make a small calculater

#include<iostream.h>
main()
{
float a, b, c, sum, mul, div, sub, average;
cout<<"enter the value of a:";
cin>>a;
cout<<"enter the value of b:";
cin>>b;
cout<<"enter the value of c:";
cin>>c;
sum=a+b+c;
mul=a*b*c;
div=a/b/c;
sub=a-b-c;
average=sum/2;
cout<<"\n sum:\t"<<sum;
cout<<"\n mul:\t"<<mul;
cout<<"\n div:\t"<<div;
cout<<"\n sub:\t"<<sub;
cout<<"\n average:\t"<<average;
}