Assuming worksales in D1:D5, days in C1:C5, meals in B1:B5, you could
use the following:

=SUMPRODUCT(--(100*$D$1:$D$5+10*$C$1:$C$5+$B$1:$B$3100*D1+10*C1 +B1))+1

Does this help?

Kostis Vezerides