Significant Figures Operations Calculators

Interactive calculators for addition, subtraction, multiplication, and division with proper significant figure rounding. Enter your own numbers and see step-by-step explanations.

Correct Rules for Sig Fig Operations:
➕ Addition & Subtraction:
  1. Align numbers by their decimal points
  2. Identify the number with the fewest decimal places
  3. Round off the other numbers so they all have the same number of decimal places as this number
  4. Complete the calculation
  5. The answer automatically has the correct number of decimal places
✖️ Multiplication & Division:
  1. Perform the calculation first with all digits (no intermediate rounding)
  2. Round the result to the least number of significant figures among the input numbers
Example - Addition:
Add: 123.45 (2 decimal places) + 0.6789 (4 decimal places)
• Fewest decimal places: 2
• Round 0.6789 to 2 decimal places → 0.68
• Calculate: 123.45 + 0.68 = 124.13
Example - Multiplication:
Multiply: 12.34 (4 sig figs) × 5.6 (2 sig figs)
• Calculate: 12.34 × 5.6 = 69.104
• Round to 2 sig figs → 69
Key Difference: For addition/subtraction, round inputs first. For multiplication/division, calculate first then round.

Addition

+
Result (with correct sig figs)
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Subtraction

-
Result (with correct sig figs)
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Multiplication

×
Result (with correct sig figs)
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Division

÷
Result (with correct sig figs)
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