I have several data tables of identical layout that are updated daily, the
first two manually and the others by preset formula that calculates from the
first two. If a zero or no data are input into cells in the first two then
the formula of the others will return #NA, this is intentional because charts
are plotted from the latter tables and #NA prevents zero's being plotted all
over it for data that has not been entered yet (zero is a valid in negative
and positive data entry only when entered).

Each table has a SUM total, but, if #NA exits in any one of the cells
totaled the
SUM is returned #NA. How can I overcome this?