PHP Warning: Loss of data on string conversion

[balexus]

<?php
     use Decimal\Decimal;
     $s = new Decimal("71.610",3);
     $e  = $s+1-1;
     echo $e;
?>

The code show warning
"PHP Warning: Loss of data on string conversion" on line 3
but if change precision from 3 to 4:
i.e.
$s = new Decimal("71.610",4);

It works

Why ?

I have noticed that same issue happen when
i use

$s = new Decimal("222.16",3);
Where is a problem ?

[rtheunissen]

Your number has 4 significant figures, so using a precision of 3 drops the last significant figure, resulting in data loss.