Piped text Math operation

Hi,
does this math operation look right ?
it basically uses the scores from a series of other scores and divides them to provide the average. for some reason its not producing any answer.
$e{ ( ( gr://SC_4VMyip3PrlyX0pw/Score + gr://SC_3TQLGucldAJqK0u/Score + gr://SC_cNNziq8dpBP7uDk/Score + gr://SC_eRHvbri1TQ4gvtk/Score + gr://SC_2srv8yuMUNwBGbc/Score + gr://SC_9QO3nJAk5gMKGDI/Score + gr://SC_1SutyIoFronvYmq/Score + gr://SC_eE9A38uGFLfX9Hg/Score ) / 8 ) }