skill~150 mindifficulty

Formulas & Functions

Functions turn a static table into a calculator that answers questions and derives new fields automatically.

1

Learn it

Formulas start with = and reference cells or ranges; functions like SUM, AVERAGE, IF, COUNTIF, and XLOOKUP package common logic. Lookups let you join information from another table by a shared key, while logical and aggregate functions summarize and classify. The skill is composing small functions into a formula that expresses your question.

By the end you’ll be able to

  • Write formulas using core functions (SUM, IF, VLOOKUP/XLOOKUP)
  • Combine functions to compute derived columns

Free resources

2

Practice

Build a summary column with IF logic and pull a matching price into each row using XLOOKUP (or VLOOKUP).

3

Build it — your output

A worksheet with calculated columns and a small summary block powered entirely by formulas.

4

Prove it — check yourself

You’re ready to move on when you can honestly say yes to each:

  • Can you write a nested IF or IFS formula?
  • Can you look up a value from another table by key?
  • Can you use COUNTIF/SUMIF to summarize by category?

Do it with AI

Use a free AI tool as your tutor and pair-programmer. Copy a prompt below into Claude, ChatGPT, or Gemini (for building, try Cursor or Copilot).

The habit: Try it yourself first — a little struggle is where the learning actually happens. Then ask for a hint before the answer — never copy blindly.

  • Understand itClaude / ChatGPT / Gemini

    I'm a beginner learning "Formulas & Functions". Explain it in simple terms with a real-world analogy, then ask me ONE question to check my understanding — don't reveal the answer.

  • PracticeClaude / ChatGPT / Gemini

    Give me 3 short practice problems on "Formulas & Functions" (my goal: write formulas using core functions (sum, if, vlookup/xlookup)), from easy to hard. Don't include the solutions yet — I'll try them first, then ask you to check.

  • Get unstuckClaude / ChatGPT / Gemini

    I'm stuck on this exercise about "Formulas & Functions": [paste your attempt here]. Give me ONE small hint to move forward — do NOT give me the full solution.

  • Build & reviewCursor / Copilot

    Here is my work for a "Formulas & Functions" task: [paste your code or answer]. Review it: point out what's wrong and WHY, and suggest improvements — but let me make the fixes myself.

  • Prove itClaude / ChatGPT / Gemini

    Quiz me on "Formulas & Functions". Ask me 5 questions one at a time, wait for my answer each time, then tell me if I'm right and briefly why.

My notes