How do _Post an array with PHP PDO prepared statements : Goodday all

I’m working on an app and get stuck with updating values in a mysql database.
When i add the name attribute manually(value1) it works fine. But when i              ‘_POST’ an array i get an error on the line beneath and i’m stucked here.

$stmt = $conn->prepare<code>("UPDATE students SET value=value+{$_POST['value']}");</code>

Error:
Notice: Array to string conversion on line 8
Error: SQLSTATE[42S22]: Column not found: 1054 Unknown column 'value' in 'field list'

For execute:
<code>$stmt->execute(array("value", $_POST['value']));</code><br><br>
This is my HTML:

    <input class="input" id="id1" name="value[]" type="range">
    <input class="input" id="id2" name="value[]" type="range">
    <input class="input" id="id3" name="value[]" type="range"> 

</html>
    The columns in mysql database are value1, value2, value3 and so on.
    For send the form i use PHP PDO prepared statements.
    Thanks in advance.

