They either used other spreadsheet applications, or calculators or paper. Excel was not the first electronic spreadsheet. Excel came out in 1985, but the first electronic spreadsheet was VisiCalc, which came out in 1979. There were others between VisiCalc and Excel, most notably Lotus 1-2-3.
Lotus Excel was created in 1982.
Excel Records was created in 1966.
Excel Maritime was created in 1988.
Surf Excel was created in 1953.
Excel Communications was created in 1988.
Excel Saga was created in 1999.
Hyundai Excel was created in 1985.
Excel Entertainment was created in 1999.
Excel Homes was created in 1984.
Kamloops Excel was created in 2007.
Excel Christian School was created in 2003.
Microsoft Excel was created by Microsoft Corporation. It was first released in 1985.