sig fig
C1technical/formal
Definition
Meaning
A digit in a number that contributes to its measurement precision.
A concept in mathematics and science indicating which digits in a measurement are reliable and meaningful, excluding leading or trailing zeros used as placeholders.
Linguistics
Semantic Notes
Primarily used in scientific, mathematical, engineering, and statistical contexts to communicate precision and reliability of numerical data.
Dialectal Variation
British vs American Usage
Differences
Terminology is identical. Regional spelling differences apply only if writing out the full phrase 'significant figure' (e.g., 'figure' not 'figur').
Connotations
None; purely technical.
Frequency
Equally frequent in UK and US technical/academic contexts.
Vocabulary
Collocations
Grammar
Valency Patterns
Noun phrase: The [number] has [X] sig figs.Verb + object: Round [the result] to [two] sig figs.Prepositional: Pay attention to the sig figs in [the measurement].Vocabulary
Synonyms
Strong
Neutral
Weak
Vocabulary
Antonyms
Phrases
Idioms & Phrases
- “Don't lose your sig figs.”
Usage
Context Usage
Business
Rare, except in technical reports involving data analysis or quality control.
Academic
Core concept in science, technology, engineering, and mathematics (STEM) education and research.
Everyday
Virtually never used.
Technical
Essential term in laboratory work, engineering design, statistical reporting, and numerical computation.
Examples
By CEFR Level
- The mass was recorded as 12.5 grams, which has three sig figs.
- You must express your answer with the correct sig figs.
- When multiplying measurements, the product should be reported with the same number of sig figs as the factor with the fewest.
- The uncertainty in the apparatus limits the result to two sig figs.
Learning
Memory Aids
Mnemonic
Sig Figs are the 'Strong Figures' in a number – the ones that truly matter for accuracy.
Conceptual Metaphor
A SIGNIFICANT FIGURE IS A TRUSTWORTHY WITNESS (provides reliable evidence about a measurement).
Watch out
Common Pitfalls
Translation Traps (for Russian speakers)
- Avoid direct calque 'значительная фигура', which implies an important person. Correct term is 'значащая цифра'.
Common Mistakes
- Confusing sig figs with decimal places.
- Incorrectly applying rules for trailing zeros after a decimal point.
- Thinking all non-zero digits are automatically significant.
- Forgetting that exact numbers (like counted items) have an infinite number of sig figs.
Practice
Quiz
Which of these numbers has exactly four significant figures?
FAQ
Frequently Asked Questions
No, leading zeros (e.g., the zeros in 0.005) are never significant; they only indicate the decimal point's position.
"Sig fig" is an informal abbreviation used primarily in speech and teaching. In formal writing, "significant figure" is preferred.
Identify the first N significant digits, then round the number to that digit, using standard rounding rules.
They communicate the precision of a measurement, preventing overstatement of accuracy and ensuring calculations reflect real-world limitations.