**Significant Figures** are used to discuss the level of precision in any measurement.

Recording Measurements

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concept

## Significant Figures Precision Concept

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so we know that significant figures will play a role in the way we analyze data, analyze questions. We also know what's gonna have an impact on the answers that we have at the end. Now there is levels of precision that are involved when it comes to significant figures. We're gonna say here the more significant figures in a measurement than the more precise it ISS. So, for example, are reading of 25.0 Emmaus is more precise than just 25. That's because 25 00 m. Els it has a decimal point. We moved from left to right. Our first non zero number here is to count all the way to the end. This has four Sig Figs 25 on the other hand, had has no decimal point. So we moved from right to left and it on. Lee has to sick fix. Since 25.0 MLS has more significant figures. It's mawr precise. It gives us more detail now when it comes to recording measurements, significant figures have to be taken into account. So we're gonna say when taking a measurement, you must include all of the known numbers, plus an additional decimal place. Now we use what I call the eyeball test. It's based on an estimate or best guess from looking. So even when looking at a measuring tape or looking at a beaker, significant figures have to be taken into account. We can't just look at the measurements or the hash marks on these tools and say that is my value because there's some level of uncertainty there. So you have tow, add an additional decimal place toe, ensure you have the correct number of significant figures. Now that we've talked about this idea of precision and measurements, click on the next video and let's put it to practice with an example question.

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example

## Significant Figures Precision Example

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Alright everyone. So here it says in this example, question determine the number of significant figures involved in measuring the length of the square. So in measuring the length of the square, we have this measurement, we see that this here is the 3.0 centimeter hash mark, And this is 3.1 and this is 3.2. So we see 3.2 cm. Remember, with the right number of significant figures, we have to add an additional decimal place. That would mean that the best answer would be 3.20 cm. Making options see our best choice.

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Problem

Read the length of the metal bar to the correct number of significant figures.

A

15 cm

B

15.000 cm

C

20 cm

D

15.0 cm

E

15.00 cm

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Problem

What is the correct reading for the liquid in the burette provided below?

A

32 mL

B

32.30 mL

C

32.26 mL

D

32.0 mL

E

32.2 mL

Additional resources for Significant Figures: Precision in Measurements

PRACTICE PROBLEMS AND ACTIVITIES (11)

- (a) What is the length of the pencil in the following figure if the ruler reads in centimeters? How many signi...
- (b) An automobile speedometer with circular scales reading both miles per hour and kilometers per hour is show...
- Report the reading on the buret to the correct number of significant figures. (LO 1.15) (a) 1 mL (b) 1.4 mL ...
- What is the temperature reading on the fol-lowing Celsius thermometer? How many sig-nificant figures do you ha...
- How many milliliters of water does the graduated cylinder in (a) contain, and how tall in centimeters is the p...
- (c) Is a graduated cylinder such as that shown in Figure 1.21 likely to afford the accuracy of measurement nee...
- An experimental procedure call for 250 mg of calcium car-bonate. The balance in the laboratory measures mass i...
- You have a graduated cylinder that contains a liquid (see photograph). Write the volume of the liquid, in mill...
- Read each measurement to the correct number of significant figures. Laboratory glassware should always be rea...
- Read each measurement to the correct number of significant figures. Laboratory glassware should always be read...
- Read each measurement to the correct number of significant figures. Laboratory glassware should always be read...