Significant Figures Practice Questions for Students

Significant Figures Practice Questions for Students (With Answers)

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Understanding significant figures is a must-have skill in science and math. Most students know the rules—but practice is where real confidence comes from. Below you’ll find carefully structured practice questions, starting from basic identification and moving toward real calculation-based problems, just like in exams.

What Are Significant Figures?

Significant figures are the digits in a number that carry meaningful information about its precision. They include:

  • All non-zero digits
  • Zeros between non-zero digits
  • Trailing zeros only if a decimal point is present

Practice Questions – Level 1 (Identify Significant Figures)

Question 1
How many significant figures are in each number?

a) 45.6
b) 0.0042
c) 300
d) 300.0
e) 7.080

Answers

a) 3 significant figures
b) 2 significant figures
c) 1 significant figure
d) 4 significant figures
e) 4 significant figures

Practice Questions – Level 2 (Rounding to Significant Figures)

Question 2
Round the following numbers to the given significant figures.

a) 12.678 → 3 significant figures
b) 0.05642 → 2 significant figures
c) 98765 → 4 significant figures
d) 4.999 → 2 significant figures

Answers

a) 12.7
b) 0.056
c) 98770
d) 5.0

Practice Questions – Level 3 (Multiplication & Division)

👉 Rule reminder:
For multiplication and division, the final answer should have the same number of significant figures as the number with the fewest significant figures.

Question 3

a) 2.4 × 3.567
b) 12.0 ÷ 4.56
c) 0.025 × 1.20

Answers

a) 8.6
b) 2.63
c) 0.030

Practice Questions – Level 4 (Addition & Subtraction)

👉 Rule reminder:
For addition and subtraction, the final answer should match the least number of decimal places.

Question 4

a) 12.45 + 3.2
b) 5.678 − 0.34
c) 100.0 + 23.456

Answers

a) 15.6
b) 5.34
c) 123.5

Practice Questions – Level 5 (Mixed Exam-Style Problems)

Question 5

a) (3.45 × 2.1) ÷ 0.056
b) 14.00 − 3.678
c) (0.0045 + 1.23) × 2.0

Answers

a) 130
b) 10.32
c) 2.5

Common Mistakes Students Should Avoid

  • Rounding too early during calculations
  • Using the wrong rule for the operation
  • Forgetting that zeros without a decimal point may not be significant
  • Mixing decimal-place rules with significant-figure rules

Quick Practice Tip

Always follow this order:

  1. Perform the full calculation without rounding
  2. Identify the limiting number (fewest sig figs or decimals)
  3. Round only at the final step

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