use POSIX;

sub ceilX ($$);

print "$_ -> ", ceilX($_, 50), "\n" for (145..154);

sub ceilX ($$) {
    my $number = shift;
    my $x      = shift;

    return POSIX::ceil($number / $x) * $x;
}

##</code><code>##

145 -> 150
146 -> 150
147 -> 150
148 -> 150
149 -> 150
150 -> 150
151 -> 200
152 -> 200
153 -> 200
154 -> 200