Reference library107 entries

Tag: significant figures

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

Oct 2026

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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Oct 2026

SQL and databases

Significant Figures in SQL and Databases: Storing and Querying Numeric Precision

Databases store numeric types and scale, not significant figures. This reference explains how to model measurement precision in SQL and round only when reporting.

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Oct 2026

Excel

How to Enter Scientific Notation in Excel, Google Sheets, and Python Without Losing Significant Figures

To enter scientific notation without losing significant figures, use numeric E-notation for calculation, custom formats or TEXT for display, and Decimal or text when…

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Oct 2026

Absolute vs Relative Error

How to Calculate Absolute and Relative Error in Excel: Rules, Formulas, and Precision Standards

Absolute error is the magnitude of the difference between a measured and reference value; relative error divides that difference by the reference value. This…

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Oct 2026

Logarithms

Significant Figures in Logarithms and pH: Why the Rules Change

In logarithms and pH, significant figures are counted in the decimal places of the result, not the integer part. The input's significant figures determine…

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Oct 2026

Excel

How to Calculate Percent Error in Excel (and Avoid Rounding Errors)

Percent error in Excel is calculated as =ABS(experimental-expected)/ABS(expected), then formatted as a percentage or multiplied by 100. Keep full precision, round only the final…

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Oct 2026

Ambiguous Trailing Zeros

Ambiguous Trailing Zeros: When a Zero Is Not Significant

Trailing zeros after a nonzero digit can be significant or merely placeholders; their status depends on notation, convention, and context.

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Oct 2026

Significant Figures

The Teacher’s Guide to Sig Fig Conventions: Why AP Chem, IB, and ASTM Disagree

A reference-grade explanation of why AP Chemistry, IB, and ASTM/ISO standards disagree on significant figures, rounding ties, and uncertainty reporting—plus how to choose the…

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