Adding a formula to an individual cell, or linking to another cell's contents


I’m making a simple budget, and I am used to using google sheets, where every cell can be a formula, so I’m trying to adapt to the Airtable way of thinking. How is Airtable meant to handle sub categories?

Please see attached image, my list on the left is the various forms of income. I want the “Total ticket income” cell to calculate an amount based on the variables to the right. The only way I could make a formula is to make an entire column for it.
But gow do I get the individual cell (highlighted in my image) to calculate those totals, without affecting the entire list of other amounts that arent relevant to it?


Every record in a Table has to be of the same type, so you can’t add a record for totals. If you want to sum totals, you have to check them on the status bar (at the bottom of the table), or link to other Table to be able to do a Rollup.