Reference library84 entries

Tag: significant figures

Practical explanations, worked examples, and reference notes for reporting numbers correctly.

Oct 2026

Why Leading Zeros Are Not Significant in the GUM: A Metrology Perspective

An authoritative explanation of why leading zeros serve only as placeholders and do not contribute to the precision of a measurement according to GUM…

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Oct 2026

Python

Sig Figs in Python: round(), format(), and Decimal — Which One Follows ASTM E29?

Python's round() and format() use half-even ties, matching ASTM E29 for exact ties, but binary floats can break decimal rounding. Decimal.quantize() is the reliable…

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Oct 2026

Measurement Uncertainty

Type A vs Type B Uncertainty: What’s the Difference and When to Use Each

Type A uncertainty is evaluated by statistical analysis of repeated observations; Type B uncertainty is evaluated by any other documented method, such as calibration…

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Oct 2026

Python

How to Round to Significant Figures in Python Using the decimal Module

Use Decimal.quantize with an exponent derived from the adjusted exponent to round to n significant figures, choosing ROUND_HALF_EVEN for standards-aligned ties.

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Oct 2026

Rounding Rules

When to Round in Multi-Step Calculations: A Decision Tree for Students and Professionals

To prevent rounding error accumulation, maintain maximum precision throughout intermediate steps and round only at the final result based on the limiting significant figure.

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Oct 2026

LaTeX siunitx

How to Round to Significant Figures in LaTeX siunitx: A Precision Reference

A comprehensive reference for rounding to significant figures with LaTeX siunitx, including syntax, standards, worked examples, counter-examples, and common pitfalls.

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Oct 2026

Measurement Uncertainty

When to Use Order of Magnitude in Uncertainty Budgets: A GUM Perspective

Order-of-magnitude estimates are useful for screening and Type B bounding in GUM uncertainty budgets, but they are not a substitute for evaluated standard uncertainties…

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Oct 2026

Significant Figures

Significant Figures Conventions Compared: School, AP, IB, ASTM E29, and GUM

A comprehensive analysis comparing academic significant figure rules with professional metrology standards like ASTM E29 and the GUM for precision reporting.

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Oct 2026

Banker's Rounding

Why Your Physics Lab Report Uses Round Half Even but Your Math Class Uses Round Half Up

Round half even and round half up differ only at exact ties, but that difference matters in physics labs, standards, software, and significant-figure reporting.

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Oct 2026

GUM Guide

GUM Uncertainty Rounding: When to Use Round Half to Even for Measurement Results

GUM result expression uses ISO 80000-1 rounding: round the expanded uncertainty to one or two significant digits, match the estimate to the same decimal…

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