#!/usr/bin/perl -w
use strict; use warnings;
use List::Util qw( sum );
printf( "You have £%.02f\n", sum (
    ( map { ask( "$_ pence pieces", $_/100 ) } ( 5, 10, 20, 50 ) ),
    ( map { ask( "£$_ coins", $_ ) } ( 1, 2 ) ),
    ( map { ask( "£$_ notes", $_ ) } ( 5, 10, 20, 50 ) ),
) );
sub ask { print "How many $_[0] do you have? " ; <STDIN> * $_[1] }