Library › Data AI › Parents and households
Measure what a mistake cost on your electric bill
Practice: Giving the right context. About 5 minutes.
About this exercise
Your July electric bill spiked because the pool heater ran by mistake for 3 weeks. Leave July out of the last 6 months to get a normal monthly average, then price July's extra use at the current rate. Write exactly 2 numbered lines: 1) the normal average with the math, 2) July's extra kWh x rate = dollars. Plain text, under 60 words, nothing else.
Common mistakes when you ask AI for this
- Averaging in the spike. The AI uses all 12 months, so the 'normal' average is too high. Try: Add: "Leave July out of the average."
- Using the old rate. The AI grabs $0.14, the first rate it sees. Try: Add: "Use the current $0.16 rate."
- Not asking to see the work. A bare dollar figure is hard to check. Try: Add a line to copy: "2. July extra: 1,600 − 750 = 850 kWh x $0.16 = $136"
- Trusting the AI to count words. AI is bad at counting. Ask for a total word limit and it often lands over it. Try: Cap each line: "each line under 20 words."
- Forgetting where it goes. AI loves markdown tables and bold, which show up as clutter in a family budget note. Try: Add: "Plain text, no bold, headings or tables."
What a strong prompt includes
- Leaves out July
- Uses the current rate
- Asks to show the math
- Sets a word limit
- Asks for plain text
Related exercises
- Announce a hybrid work policy change with clear actions (Writing AI · HR and recruiting)
- Announce a new weekend rotation in three clear rules (Productivity AI · Managers and team leads)
- Announce a promotion with the right date and no pay details (Writing AI · HR and recruiting)
- Announce a team change and answer the first question (Writing AI · Managers and team leads)
- Answer a showing request for a home that's under contract (Writing AI · Real estate agents)