The Value value from final Variable Give me minus : I try to make some some with various variables and it should give 200 on final response But It Give me -200 What Is Wrong With My Code Why It give -200 i want it to give me 200 on final some
My App Send An Ajax call With a variable $Points but for security i have made a some with more two variables
for example if the user have 200 points the app it will add the ntruck=412020 and truck=20201 
so on final it send to the php script the value 432221+200=432421
wen the script is load it take from total 432421-ntruck-truck so it will stay only the value of the points 200
This Is my code:

<!-- begin snippet: js hide: false -->

<!-- language: lang-html -->

    <?php
    $point = "432421";
    $ntruck = "412020";
    $truck = "20201";
    $sum_total = $truck + $ntruck;
    $npoints = $sum_total - $point;
    $points = $npoints;
    echo $points;
    ?>

<!-- end snippet -->

But Wen I Make An Echo It Give me minus -200 where i have failed 