#!/usr/bin/perl
use strict;
use warnings;

open (NUMBERS, '<', "numbers.txt") or die "Unable to open numbers.txt for reading : $!";
open (NAMES, '<', "names.txt") or die "Unable to open names.txt for reading : $!";

my %numbers = map {chomp; $_ => 1} <NUMBERS>;
my %names = map {chomp; split /\t/ , $_ , 2} <NAMES>;

for my $name ( keys %names ) {
    my $names_number = $names{$name};
    for my $number ( keys %numbers ) {
        my $delta = abs $number - $names_number;
        if ( $delta <= .5 ) {
            print "$name : $names_number is within range of $number\n";
            last;
        }
    }
}