Which tool to choose
For small tables, pasting the data directly into the message is the quickest way. For real files, upload the sheet if your assistant reads this type of file; otherwise, export or copy the part you need and paste it. The reliable calculation tool remains Excel or the spreadsheet you use: the AI is the mind that explains things to you, builds the formulas and reads the trends, but the definitive calculation is best left to the sheet, which doesn't get the operations wrong.
How to do it
- Bring the table into the chat: upload the file or paste the data with the column headers.
- Ask precise questions: "what's the average of this column?", "write me the formula to sum only the March rows," "what do you notice in this data?".
- For formulas, ask for the one to paste into the sheet, not just the result.
- Verify in the sheet the numbers that matter: paste in the formula and check it adds up.
A concrete example
Giulia had a table of monthly expenses and didn't know how to sum only those of a certain category. She pasted the data into the chat and asked: give me the formula to sum only the expenses in the "transport" category. The AI explained the right formula to her and wrote it ready to paste into her sheet. Giulia put it into Excel, and the total appeared. She didn't ask the AI to do the sum by hand — she used it to build the tool, and left the calculation to the sheet, which on that is infallible.
When it does NOT work (and how to fix it)
If the AI gets a calculation wrong
It happens, especially with lots of numbers or long operations: the AI reasons, it isn't a calculator. The solution is not to ask it for the result but for the formula, to be calculated by the sheet. For quick checks, recheck the important numbers instead of trusting the count done in the chat.
If the table is large and complex
Huge files can exceed what the AI holds together. Work on a portion, or describe its structure to it (which columns, what they contain) and ask for the formula or the approach, which you then apply to the whole sheet yourself.
If the data is pasted badly and the AI gets confused
When you paste a table, the columns can mix and become illegible. Help it by saying what each column contains, or upload the file instead of pasting. Clear data in gives clear answers out.
A tip from someone who really uses it
Use the AI to understand and build, the sheet to calculate. It's the division of tasks that gives you the best of both: the assistant is unbeatable at explaining to you what a complicated formula does, at building one for you starting from what you want to get, and at reading at a glance what your data tells. The spreadsheet is unbeatable at doing the math without errors. Whoever asks the AI to do the sums in Excel's place exposes themselves to needless errors; whoever asks it for the formula to paste gets a precise, reusable tool. The power isn't choosing one of the two, it's making them work together.
Frequently asked questions
Can I trust the calculations done by the AI?
For estimates and reasoning yes, for exact numbers no: it can get the operations wrong. The safe practice is to have it give you the formula and calculate in the sheet, or to verify the important results.
Can the AI write complicated formulas for me?
Yes, and it's one of its best uses: you describe what you want to get and it builds the formula, explaining it to you. Then you paste it into the sheet and reuse it whenever you want.
What's the difference between uploading the file and pasting the data?
Uploading the file preserves the structure and is good for ordered tables; pasting is quicker for a few rows but risks mixing the columns. If the AI gets confused on the pasted data, try uploading the file or describing the columns.
The AI is like a calculator, so the math is always right?
No, and it's a misunderstanding that leads to silent errors. The AI doesn't calculate like a calculator: it reasons over the text of the numbers, and on long operations or many digits it can get it wrong while staying confident. The result looks right and maybe isn't. That's why the numbers that matter should be calculated by the sheet, not by the chat: ask the AI for the formula and the explanation, ask Excel for the count. Treating the assistant like an infallible calculator is the most common way to take home a wrong total without noticing.