Here is Jochen's 155
 Code:
function a($x)
    dim $v, $b, $
    while $x
        $ = left($x,1)
        $x = right($x,~)
        if $>!
            $v = ($=X)*10 + $ + ($="/")*(10-$v)
            $a = $a + ($b-($b>1)+1)*$v
            $b = ($b>1) + (2*($=X)^$="/")*($x<!)
endfunction