#!/usr/bin/perl
print "What is your name?\n";
$name = <>;
chomp($name);
$greeting = "Hello, " . $name . "\nWhat do type of math do you want this program to do?\n";
print $greeting;
chomp($operator = <STDIN>);
if ($operator eq 'sub') {
  $c = $a - $b;
} elsif ($operator eq '*') {
  # * code here
} else {
 $c = 'invalid operator';
}