When you concatenate text, you surround the text with double quotation marks so Microsoft Excel recognizes it as text. Otherwise, you'll receive an error. Excel then ...

If I enter the following:<BR><BR>=CONCATENATE("Design Avg. Flow per Cell = ",J12," g.p.d. / ",J21," Cells")<BR><BR>where J12=6300 and J21=3, I get<BR><BR>Design Avg ...