四舍五入到一位小数

I am using a function to make 1000 to 1k and 1000000 to 1m but i want to add one decimal to it, i have gotten this far but it rounds up instead of down so if i enter 1565 i want to get 1.5 and only if i pass 1600 i want to get 1.6 (force round down) i use this function:

public function convert($Input){
    if($Input<1000){
        $AmountCode = "";
        $Amount = $Input;
    }
    else if($Input>=1000000){
        $AmountCode = "M";
        $Amount = round(floatval($Input / 1000000), 1, PHP_ROUND_HALF_DOWN);
    }
    else if($Input>=1000){
        $AmountCode = "K";
        $Amount = round($Input / 1000, 1, PHP_ROUND_HALF_DOWN);

    }

    $Array = array(
        'Amount' => $Amount,
        'Code' => $AmountCode
    );

    return $Array;

}

Scenario 1: what happens now if i enter 1565 i get 1.6 and if i enter 1545 i get 1.5 does any one know how to get the forcibly round it down?

Scenario 2: the number i enter is 10665 will be outputted as 10.7k (rounded up), but i want to to show as 10.6k (rounded down) which for somereason i can't figure out how to do that

For rounding down in PHP, they have a function called floor(). Unfortunatly, this function does only return an int. However you can make it round down by multiplication first, and then division. See this post: PHP How do I round down to two decimal places?.

This means your code would be something like this:

else if($Input>=1000000){
    $AmountCode = "M";
    $Amount = floor(floatval($Input / 100000))/10;
}
else if($Input>=1000){
    $AmountCode = "K";
    $Amount = floor(floatval($Input / 100))/10;

}