Significance of Zeros in Numbers
Introduction
Understanding when zeros in a number are considered significant is crucial for precise scientific calculations and measurements. The significance of zeros depends on their position relative to non-zero digits.
Rules for Significant Zeros
1. Zeros Sandwiched Between Non-Zero Digits
- Rule: Zeros located between non-zero digits are always significant.
- Examples:
- In the number 391, all digits, including the zero, are significant (total: 4 significant figures).
- 82,024 also includes a significant zero (total: 5 significant figures).
- 109,003 has zeros that are sandwiched and thus significant (total: 6 significant figures).
- The presence of decimal points does not affect the significance of sandwiched zeros.
2. Leading Zeros
- Rule: Zeros that precede non-zero digits are never significant.
- Examples:
- 0.0000491 has three significant figures (4, 9, 1).
- 0.01322 has three significant figures (1, 3, 2).
- 0.00000062 has two significant figures (6, 2).
3. Trailing Zeros
- Zeros without a decimal point:
- Rule: Zeros that follow non-zero digits are not significant if there is no decimal point.
- Example: 83,000 – only 8 and 3 are significant (total: 2 significant figures).
- Zeros with a decimal point:
- Rule: Zeros that follow a decimal point are significant.
- Examples:
- 83,000. (with a decimal) has 5 significant figures.
- 83.000 has 5 significant figures because of the decimal.
Additional Examples
- 4,532,100 without a decimal point has 5 significant figures.
- 7,890,000 with a decimal point has 6 significant figures.
- 90,000 without a decimal point has 2 significant figures.
- 200. with a decimal point includes all digits as significant (total: 3 significant figures).
- 50.000 has 5 significant figures due to the decimal point.
Summary
- Trailing zeros are significant if there is a decimal point present.
- Leading zeros are never significant.
- Practice with examples to reinforce understanding of when zeros are significant.
Conclusion
The key to mastering the significance of zeros is practice. By working through examples, students can gain a strong grasp of these concepts, ensuring accurate scientific computations.