So now they're still counting up, and have not memorized these basic facts.
So I had the idea that we need to give them sheets with practice problems, like the timed ones they do in school. I figure if they have to do this a lot, then eventually the facts will just "sink in".
This is when the wife pipes up: "hey can you write a program to do that?" (If only I had a nickel for every time the wife asked "can you write a program to do that?"...)
Well, this one was easy, took me about 20 minutes in perl. I wrote a script, "problems.pl" that dumps text file of some 144 problems suitable for sending to the printer. Here's sample output:
gdamore@pepper{18}> perl ~/problems.pl -r
Practice: (# 650)
Times tables from 1 to 12.
All mixed up!
4 x 7 = 5 x 7 = 1 x 10 = 2 x 9 = 10 x 9 = 6 x 7 =
12 x 10 = 1 x 4 = 2 x 5 = 6 x 3 = 5 x 12 = 11 x 8 =
2 x 12 = 1 x 1 = 7 x 4 = 3 x 10 = 9 x 10 = 6 x 11 =
Command line switches: "-r" to randomize the problems a bit (although every problem is given), "-s
Here's the code. Feel free to pass it around, give it away, modify it, whatever. It can be adapted to other kinds of problems pretty easily, I expect. Maybe you know a teacher or parent who could use this dumb little script. Maybe you just need to practice your multiplication tables on your own? I won't tell!
#!/usr/bin/perl
use Getopt::Std;
my $start = 1;
my $end = 12;
my @problems;
sub usage() {
print STDERR basename($0), ": usage\n";
print STDERR "problems: [ -r ] [ -a ] [ -s] [ -e ]\n";
exit(2);
}
srand();
$seed = int(rand(1000));
my $s, $e, $i, $j;
getopts('rs:e:aS:', \%opt) || usage;
$dorand = exists($opt{'r'});
$doans = exists($opt{'a'});
$start = $opt{'s'} if exists($opt{'s'});
$end = $opt{'e'} if exists($opt{'e'});
$seed = $opt{'S'} if exists($opt{'S'});
srand($seed);
$i = 0;
$s = $start;
$idx = 0;
foreach $i (1..12) {
foreach $j (1..12) {
$problems[$idx]->{'problem'} =
sprintf("%2d x %2d = ", $s, $j);
$problems[$idx]->{'answer'} =
sprintf("%2d x %2d =%3d " , $s, $j, $s * $j);
$problems[$idx]->{'defined'} = 1;
$idx = $idx + 1;
}
$s = $s + 1;
if ($s > $end) {
$s = $start;
}
}
@new = ();
if ($dorand) {
for( @problems ){
my $r = rand @new+1;
push(@new,$new[$r]);
$new[$r] = $_;
}
} else {
@new = @problems;
}
if ($doans) {
printf("\tAnswers: %s\n", $dorand ? "(# $seed)" : "");
} else {
printf("\tPractice: %s\n", $dorand ? "(# $seed)" : "");
}
printf("\tTimes tables from $start to $end.\n");
if ($dorand) {
printf("\tAll mixed up!\n");
}
printf("\n\n");
foreach $x (0 .. 1) {
$idx = $x * (72);
for $y ( 1 ..12) {
if ($doans) {
printf("%s%s%s%s%s%s\n",
$new[$idx]->{'answer'},
$new[$idx + 12]->{'answer'},
$new[$idx + 24]->{'answer'},
$new[$idx + 36]->{'answer'},
$new[$idx + 48]->{'answer'},
$new[$idx + 60]->{'answer'},
$new[$idx + 72]->{'answer'});
printf("\n");
} else {
printf("%s%s%s%s%s%s\n",
$new[$idx]->{'problem'},
$new[$idx + 12]->{'problem'},
$new[$idx + 24]->{'problem'},
$new[$idx + 36]->{'problem'},
$new[$idx + 48]->{'problem'},
$new[$idx + 60]->{'problem'},
$new[$idx + 72]->{'problem'});
printf("\n");
}
$idx = $idx + 1;
}
}
