$a = 1;
$b = 1;
$c = 0;

while ($c <= 100)
{
if     ($c == 10 AND $b != 2 AND $b != 5 AND $b != 10)
{
    $b++;
    $a-=10;
    echo "<br>";
}
elseif ($c == 20 AND $b != 4 AND $b != 5 AND $b != 10)
{
    $b++;
    $a-=10;
    echo "<br>";
}
elseif ($c == 30 AND $b != 5 AND $b != 6 AND $b != 10)
{
    $b++;
    $a-=10;
    echo "<br>";
}
elseif ($c == 40 AND $b != 5 AND $b != 8 AND $b != 10)
{
    $b++;
    $a-=10;
    echo "<br>";
}
elseif ($c == 50 AND $b != 10)
{
    $b++;
    $a-=10;
    echo "<br>";
}
elseif ($c == 60 AND $b != 10)
{
    $b++;
    $a-=10;
    echo "<br>";
}
elseif ($c == 70 AND $b != 10)
{
    $b++;
    $a-=10;
    echo "<br>";
}
elseif ($c == 80 AND $b != 10)
{
    $b++;
    $a-=10;
    echo "<br>";
}
elseif ($c == 90 AND $b != 10)
{
    $b++;
    $a-=10;
    echo "<br>";
}
elseif ($c == 100 AND $b != 10)
{
    $b++;
    $a-=10;
    echo "<br>";
}
$c = $a * $b;
echo "$a*$b=$c<br>";
$a++;
}