Spreadsheet for Joomla

I have setup the spreadsheet on Joomla site and can input data, however I cannot find any maths functions. Tried =sum(a1:a4) but nothing happened. I am new to this so any advise would be helpful.

ok worked it out for myself; the following is ther remedy for anyone who has not got the math function working.
in the zip file you will find a file called spreadsheet_common.php,
open this using notepad
Select edie from the menu
type math in the search box and you will see this;

public function get_spreadsheet_client() {
$uid = $this->uid();
$cfg = “var cfg = {\n\t”;
$cfg .= “sheet: '”.($this->get(‘id’) ? $this->get(‘id’) : ‘1’)."’,\n\t";
$cfg .= “dhx_rel_path: ‘{$this->get(‘plugin’)}codebase/’,\n\t”;
$cfg .= “parent: ‘spreadsheet_box_{$uid}’,\n\t”;
$cfg .= “load: ‘{$this->get(‘connector’)}’,\n\t”;
$cfg .= “save: ‘{$this->get(‘connector’)}’,\n”;
$cfg .= “skin: '”.($this->get(‘skin’) ? $this->get(‘skin’) : ‘dhx_skyblue’)."’,\n";
$cfg .= “math: “.($this->get(‘math’) ? $this->get(‘math’) : ‘false’).”,\n”;change the math function from false to true
save the file and your math functions should not be working.