Significant Figures

Don’t claim more than you know

An interactive lesson with 6 steps, about 5 minutes: you predict, drag and solve, with instant feedback on every answer. It runs in your browser and needs JavaScript.

What you’ll learn

• Significant figures are the digits that carry real information; leading zeros don’t count.
• Multiplying/dividing: keep the fewest significant figures. Adding/subtracting: the fewest decimal places.
• The last recorded digit is usually an estimate.

Steps

1. Digits that mean something
2. Count them
3. Read the ruler
4. Rules for calculations
5. Area of a card
6. Avogadro’s number