Significant figures (sig figs) are a crucial part of scientific... Show more
Chemistry97 views·Updated May 17, 2026·2 pagesMaster the Concept of Significant Figures in Chemistry
A
Athena Pacheco@athenapacheco_rfik
1
of 2
Understanding Significant Figures
Significant figures tell us which digits in a measurement are reliable. When you measure something, not all the digits in your result have the same level of certainty.
The rules for counting significant figures are straightforward. Non-zero numbers are always significant, and zeros between non-zero numbers count too. Placeholder zeros don't count, but zeros after non-zero digits are significant if there's a decimal point in the number.
Scientific notation helps express numbers clearly. For example, 1500 becomes 1.5×10³ by moving the decimal point three places left. Similarly, a very small number like 0.00231 becomes 2.31×10⁻³ by moving the decimal point three places right.
Quick Tip: When in doubt about significant figures in a number, try converting it to scientific notation. The digits you write in the coefficient (the part before the 10) are your significant figures!
Practicing sig fig identification is essential. For instance, 35g has 2 sig figs, 3.507km has 4 sig figs, and 0.0035kg has only 2 sig figs (the zeros at the beginning are just placeholders). Remember that all digits after the decimal in a number like 240.00g are significant - giving it 5 sig figs total.
2
of 2
Using Significant Figures in Calculations
When doing math with measurements, you need to follow specific rules for significant figures to maintain proper precision. These rules differ depending on the operation you're performing.
For addition and subtraction, your answer should have the same number of decimal places as the measurement with the fewest decimal places. For example, when adding 34.234 + 22.4, the answer must be rounded to 56.6 (one decimal place) because 22.4 only has one decimal place.
For multiplication and division, your answer should have the same number of significant figures as the measurement with the fewest sig figs. If you multiply 3.01 × 2.0, your answer should be 6.0 (two sig figs) because 2.0 has only two significant figures.
Remember: In science, reporting a measurement with too many significant figures is just as incorrect as reporting too few - it misrepresents the precision of your data!
Rounding numbers correctly is an essential skill. To round 3.515014 to 5 sig figs, you get 3.5150. When rounding to fewer sig figs, like rounding 3.52 to 1 sig fig, you get 4 because the "5" causes you to round up. For large numbers like 136,758 rounded to 4 sig figs, you get 136,800 or 1.368×10⁵ in scientific notation.
We thought you’d never ask...
What is the Knowunity AI companion?
Our AI companion is specifically built for the needs of students. Based on the millions of content pieces we have on the platform we can provide truly meaningful and relevant answers to students. But its not only about answers, the companion is even more about guiding students through their daily learning challenges, with personalised study plans, quizzes or content pieces in the chat and 100% personalisation based on the students skills and developments.
Where can I download the Knowunity app?
You can download the app in the Google Play Store and in the Apple App Store.
Is Knowunity really free of charge?
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
Similar Content
Most popular content: Chemical Calculations
2Most popular content in Chemistry
9ChemistryMass-to-Mass Stoichiometry: Calculating Grams to Grams
Learn how to perform mass-to-mass stoichiometric calculations. This guide covers the steps to convert grams of a reactant or product to grams of another substance using mole ratios and molar mass.
9th1832
I
ChemistryIntro to Chem - Test Review
Identifying elements, compounds, heterogeneous/homogeneous mixtures and chemical/physical change test review.
11th1963
ChemistryMolecular Geometry
Chemistry notes
10th1410
ChemistryUnderstanding Atomic and Mass Numbers (Z and A)
Learn the definitions of atomic number (Z) and mass number (A). Understand how these numbers relate to protons, neutrons, and isotopes in an atom's nucleus.
9th492
ChemistryThermochemistry Notes 🥵🔥
Unit 10 of Chemistry Honors (Inorganic)
10th87052
ChemistryPOGIL Stoichiometry
mole to mole, mole to mass, mass to mass, and volume conversions
10th4652
ChemistryChemistry: Atoms, Molecules, Ions
This is about atoms, molecules and ions.
9th1337
ChemistryIsomerism
Structural and sterioisomers (geometric and optical)
11th791
ChemistryAcids and Bases
This tackles the general properties of acids and bases, their examples and pH concept.
1311
Most popular content
9O
AP US HistoryOrigins and Dynamics of the Columbian Exchange
Analyze the ecological and economic motivations behind the initial transfer of goods, people, and diseases between the Old and New Worlds.
9th3,1280
I
AP US HistoryIntroduction to Early Cultural Interactions
Analyze the initial social and religious encounters between Europeans, Africans, and Indigenous peoples in the colonial Americas.
9th2,7730
O
AP World HistoryOrigins of Ancient River Civilizations
Analyze the environmental factors and technological innovations that led to the rise of early states in Mesopotamia, Egypt, and the Indus Valley.
9th3,1860
M
AP US HistoryMotivations for European Exploration
Analyze the economic, religious, and political factors that drove European powers to the Americas during the 15th and 16th centuries.
9th1,7780
F
AP PsychologyFoundations of Ethical Guidelines in Research
Practice the core principles of the APA ethical code including informed consent, debriefing, and the role of Institutional Review Boards.
9th1,3360
I
AP US HistoryIntroduction to Native American Societies
Examine the diverse social, political, and economic structures of North American indigenous groups prior to European contact.
9th1,1100
I
AP BiologyIntroduction to Biological Elements of Life
Practice identifying the essential elements including carbon, nitrogen, phosphorus, and sulfur that compose biological macromolecules.
9th1,7360
I
AP US HistoryIntroduction to the Spanish Encomienda System
Explore the fundamental economic and social structures of the Spanish colonial system, focusing on the encomienda and the casta social hierarchy.
9th8890
O
AP World HistoryOrigins and Continuity of the Byzantine Empire
Analyze the political and cultural transitions from the Roman Empire to the Byzantine Empire, focusing on the reign of Justinian I and his code.
9th1,6320
Can't find what you're looking for? Explore other subjects.
Students love us — and so will you.
4.6/5App Store
4.7/5Google Play
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan SiOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha KlichAndroid user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
AnnaiOS user
Chemistry97 views·Updated May 17, 2026·2 pagesMaster the Concept of Significant Figures in Chemistry
A
Athena Pacheco@athenapacheco_rfik
Significant figures (sig figs) are a crucial part of scientific measurements that tell us how precise our numbers are. Learning to count, use, and round sig figs correctly will help you perform accurate calculations in science classes and avoid unnecessary... Show more
1
of 2Sign up to see the content. It's free!
- Access to all documents
- Improve your grades
- Join milions of students
Understanding Significant Figures
Significant figures tell us which digits in a measurement are reliable. When you measure something, not all the digits in your result have the same level of certainty.
The rules for counting significant figures are straightforward. Non-zero numbers are always significant, and zeros between non-zero numbers count too. Placeholder zeros don't count, but zeros after non-zero digits are significant if there's a decimal point in the number.
Scientific notation helps express numbers clearly. For example, 1500 becomes 1.5×10³ by moving the decimal point three places left. Similarly, a very small number like 0.00231 becomes 2.31×10⁻³ by moving the decimal point three places right.
Quick Tip: When in doubt about significant figures in a number, try converting it to scientific notation. The digits you write in the coefficient (the part before the 10) are your significant figures!
Practicing sig fig identification is essential. For instance, 35g has 2 sig figs, 3.507km has 4 sig figs, and 0.0035kg has only 2 sig figs (the zeros at the beginning are just placeholders). Remember that all digits after the decimal in a number like 240.00g are significant - giving it 5 sig figs total.
2
of 2Sign up to see the content. It's free!
- Access to all documents
- Improve your grades
- Join milions of students
Using Significant Figures in Calculations
When doing math with measurements, you need to follow specific rules for significant figures to maintain proper precision. These rules differ depending on the operation you're performing.
For addition and subtraction, your answer should have the same number of decimal places as the measurement with the fewest decimal places. For example, when adding 34.234 + 22.4, the answer must be rounded to 56.6 (one decimal place) because 22.4 only has one decimal place.
For multiplication and division, your answer should have the same number of significant figures as the measurement with the fewest sig figs. If you multiply 3.01 × 2.0, your answer should be 6.0 (two sig figs) because 2.0 has only two significant figures.
Remember: In science, reporting a measurement with too many significant figures is just as incorrect as reporting too few - it misrepresents the precision of your data!
Rounding numbers correctly is an essential skill. To round 3.515014 to 5 sig figs, you get 3.5150. When rounding to fewer sig figs, like rounding 3.52 to 1 sig fig, you get 4 because the "5" causes you to round up. For large numbers like 136,758 rounded to 4 sig figs, you get 136,800 or 1.368×10⁵ in scientific notation.
We thought you’d never ask...
What is the Knowunity AI companion?
Our AI companion is specifically built for the needs of students. Based on the millions of content pieces we have on the platform we can provide truly meaningful and relevant answers to students. But its not only about answers, the companion is even more about guiding students through their daily learning challenges, with personalised study plans, quizzes or content pieces in the chat and 100% personalisation based on the students skills and developments.
Where can I download the Knowunity app?
You can download the app in the Google Play Store and in the Apple App Store.
Is Knowunity really free of charge?
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
Similar Content
Most popular content: Chemical Calculations
2Most popular content in Chemistry
9ChemistryMass-to-Mass Stoichiometry: Calculating Grams to Grams
Learn how to perform mass-to-mass stoichiometric calculations. This guide covers the steps to convert grams of a reactant or product to grams of another substance using mole ratios and molar mass.
9th1832
I
ChemistryIntro to Chem - Test Review
Identifying elements, compounds, heterogeneous/homogeneous mixtures and chemical/physical change test review.
11th1963
ChemistryMolecular Geometry
Chemistry notes
10th1410
ChemistryUnderstanding Atomic and Mass Numbers (Z and A)
Learn the definitions of atomic number (Z) and mass number (A). Understand how these numbers relate to protons, neutrons, and isotopes in an atom's nucleus.
9th492
ChemistryThermochemistry Notes 🥵🔥
Unit 10 of Chemistry Honors (Inorganic)
10th87052
ChemistryPOGIL Stoichiometry
mole to mole, mole to mass, mass to mass, and volume conversions
10th4652
ChemistryChemistry: Atoms, Molecules, Ions
This is about atoms, molecules and ions.
9th1337
ChemistryIsomerism
Structural and sterioisomers (geometric and optical)
11th791
ChemistryAcids and Bases
This tackles the general properties of acids and bases, their examples and pH concept.
1311
Most popular content
9O
AP US HistoryOrigins and Dynamics of the Columbian Exchange
Analyze the ecological and economic motivations behind the initial transfer of goods, people, and diseases between the Old and New Worlds.
9th3,1280
I
AP US HistoryIntroduction to Early Cultural Interactions
Analyze the initial social and religious encounters between Europeans, Africans, and Indigenous peoples in the colonial Americas.
9th2,7730
O
AP World HistoryOrigins of Ancient River Civilizations
Analyze the environmental factors and technological innovations that led to the rise of early states in Mesopotamia, Egypt, and the Indus Valley.
9th3,1860
M
AP US HistoryMotivations for European Exploration
Analyze the economic, religious, and political factors that drove European powers to the Americas during the 15th and 16th centuries.
9th1,7780
F
AP PsychologyFoundations of Ethical Guidelines in Research
Practice the core principles of the APA ethical code including informed consent, debriefing, and the role of Institutional Review Boards.
9th1,3360
I
AP US HistoryIntroduction to Native American Societies
Examine the diverse social, political, and economic structures of North American indigenous groups prior to European contact.
9th1,1100
I
AP BiologyIntroduction to Biological Elements of Life
Practice identifying the essential elements including carbon, nitrogen, phosphorus, and sulfur that compose biological macromolecules.
9th1,7360
I
AP US HistoryIntroduction to the Spanish Encomienda System
Explore the fundamental economic and social structures of the Spanish colonial system, focusing on the encomienda and the casta social hierarchy.
9th8890
O
AP World HistoryOrigins and Continuity of the Byzantine Empire
Analyze the political and cultural transitions from the Roman Empire to the Byzantine Empire, focusing on the reign of Justinian I and his code.
9th1,6320
Can't find what you're looking for? Explore other subjects.
Students love us — and so will you.
4.6/5App Store
4.7/5Google Play
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan SiOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha KlichAndroid user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
AnnaiOS user