I thought I had already posted this, but since I can't find it today I will try again.

No matter what application you choose your difficulty is going to be finding a version of the app that will work with your elderly MacOS version, but you might check out OpenOffice or NeoOffice (variations on the same open source code base). The spreadsheet module in either is arguably more powerful than Numbers although perhaps not as visually glitzy and likely will solve your problem. You will have to do some digging on their web sites to find a version that will work with your MacOS however.

If we knew what it was we were doing, it wouldn't be called research, would it?

— Albert Einstein