Skip to main content
Ch.1 - Matter, Measurement & Problem Solving
Chapter 1, Problem 77

How many significant figures are in each number? a. 0.000312 m b. 312,000 s c. 3.12 × 105 km d. 13,127 s e. 2000

Verified step by step guidance
1
Identify the non-zero digits in each number, as they are always significant.
For numbers with leading zeros, such as in part (a), note that leading zeros are not significant.
For numbers with trailing zeros, such as in part (b) and (e), determine if the zeros are significant by checking if there is a decimal point present.
For numbers in scientific notation, such as in part (c), focus on the digits in the coefficient (the number before the multiplication sign) as they are significant.
For whole numbers without a decimal point, such as in part (d), consider all non-zero digits as significant and evaluate if any trailing zeros are significant based on context or additional information.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
1m
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Significant Figures

Significant figures are the digits in a number that contribute to its precision. This includes all non-zero digits, any zeros between significant digits, and trailing zeros in the decimal portion. Understanding significant figures is crucial for accurately reporting measurements and calculations in scientific contexts.
Recommended video:
Guided course
01:09
Significant Figures Example

Leading Zeros

Leading zeros are the zeros that precede all non-zero digits in a number. They are not considered significant because they do not affect the value of the number. For example, in the number 0.000312, the leading zeros do not count towards the significant figures, which are only the '312'.
Recommended video:
Guided course
02:44
Zero-Order Reactions

Trailing Zeros

Trailing zeros are the zeros that follow non-zero digits in a number. Their significance depends on the presence of a decimal point. For instance, in the number 312,000, the trailing zeros are ambiguous without a decimal point, while in 2000, they are not considered significant unless specified otherwise (e.g., 2000. has four significant figures).
Recommended video:
Guided course
02:44
Zero-Order Reactions