← Day 19
UNIT 7 / 8 · LESSON 2 / 4 · 23 MINUTES

Read labels before doing arithmetic

Most graph errors come from the wrong axis, unit, category, or denominator.

01 / THE METHOD

Make it repeatable

  1. Read title, axes, legend, and units.
  2. Locate the exact row or category asked about.
  3. Compute only the relevant comparison.
  4. State the result with units and direction.
02 / WORKED EXAMPLE

Watch the method in action

A table reports 270 votes for vanilla and 230 for chocolate out of 500. Estimate the vote difference in a town of 10,000.
  1. Survey difference: 40 votes out of 500.
  2. Scale factor: 10,000 ÷ 500 = 20.
  3. Expected difference: 40 × 20 = 800.

Vanilla is expected to lead by 800 votes.

03 / QUICK CHECK

Try it yourself

What is the scaled vote difference?

04 / PRACTISE AND CHECK

Apply the method to real questions

Start with guided questions and feedback. Then take a fresh independent set without hints. Reach at least 80% on that set to record this lesson.

Pass the quick check above to unlock practice.