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Significant Digits Practice Quiz
Sharpen skills with a significant digits test
Study Outcomes
- Understand the rules for identifying significant digits in numerical values.
- Apply proper rounding techniques based on significant digit guidelines.
- Analyze measurement precision and its impact on scientific calculations.
- Evaluate numerical results to determine the appropriate number of significant digits.
- Synthesize significant digit concepts to solve real-world scientific problems.
Significant Digits Cheat Sheet
- All non-zero digits are significant. Every digit from 1 through 9 always counts, so in 123.45 you've got five significant figures. This rule helps you keep track of precision in every calculation. Pearson: Significant Figures
- Zeros between non-zero digits are significant. In a number like 1002, both zeros sandwiched between the 1 and 2 matter, giving you four significant figures. Remember that any zero "trapped" between other digits is a VIP. Pearson: Significant Figures
- Leading zeros are not significant. In 0.056, the zeros merely set the decimal place, so only 5 and 6 actually count. Think of those zeros as quiet placeholders waiting in the wings. Pearson: Significant Figures
- Trailing zeros in a decimal number are significant. A value like 78.00 boasts four significant figures because those zeros after the decimal point are rock stars. They lock in your measurement's exactness. Pearson: Significant Figures
- Trailing zeros in a whole number without a decimal point are ambiguous. In 1500, it's unclear if those zeros count unless you see a decimal or overbar. To clear up the mystery, consider using scientific notation. Pearson: Significant Figures
- Addition & subtraction rule: Your answer should have the same number of decimal places as the measurement with the fewest decimals. For example, 150.0 g + 0.507 g becomes 150.5 g - not 150.507 g. Purdue: Sig Figs Guide
- Multiplication & division rule: Match the number of significant figures in your result to the measurement with the fewest sig figs. If you multiply 4.56 (three sig figs) by 1.4 (two sig figs), your answer gets two sig figs. Purdue: Sig Figs Guide
- Exact numbers have infinite significant figures. Defined quantities like 1 m = 100 cm don't limit your digits - they're considered perfect. Use them freely without worrying about losing precision. Britannica: Significant Figures
- Rounding rules: If the digit to the right is less than 5, round down; if it's greater than 5, round up. For instance, 33.742 rounded to one decimal place is 33.7. This keeps your numbers neat! Britannica: Significant Figures
- Use scientific notation to show sig figs clearly. Writing 4.5 × 10³ makes it obvious you have two significant figures and avoids any zero drama. This trick is especially handy for huge or tiny numbers. Britannica: Significant Figures