Significant Figures

1 / 15

Significant Figures - PowerPoint PPT Presentation

4.5678. 600. 0.5008. Significant Figures. 1.004. 8. 9.99999. 32.000. 7. 2.45. Measurement always involves some estimating. The more accurate a measurement is, the closer it is to the true value.

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.

PowerPoint Slideshow about ' Significant Figures' - uyen

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

4.5678

600

0.5008

Significant Figures

1.004

8

9.99999

32.000

7

2.45

Measurement always involves some estimating.

The more accurate a measurement is, the closer it is to the truevalue.

A better instrument allows for better measurements, recorded as a greater number of significant figures (digits).

Recording - include EVERY digit that is absolutely certain...PLUS the ONE digit that is estimated.

These are the SIGNIFICANT FIGURES.

3.2

3

estimated

certain

1. All non-zero digits are significant.

374 (3 sig figs) 8.1 (2 sig figs)

2. All zeroes between non-zero digits are significant.

50407(5 sig figs) 8.001(4 sig figs)

0.54(2 sig figs) 0.0098(2 sig figs)

Always LOOK FOR A DECIMAL

4. Trailing zeroes are significant ONLY if there is a

decimal point.

2370(3 sig figs) 16000(2 sig figs)

160.0(4 sig figs) 000.1800 (4 sig figs)

ALL digits in scientific notation are SIGNIFICANT

6.02 x 10 23

• Move the decimal so it is behind the first
• non-zero digit.
• Count the number of places that you moved the
• decimal - to the left is +, right is -

238000 2.38 x 10 5

0.0052 5.2 x 10 -3

1.5 x 10 4 15 000

6.35 x 10 -4 0.000635

• 103,000
• 1,236,000
• 42.0
• 0.00000021
• 5. 0.000238

1.03 x 10 5

1.236 x 10 6

4.20 x 10 1

2.1 x 10 -7

2.38 x 10 -4

Rounding Rules

0-4: round down

5 -9: round up

0.00533(2 sig figs) 0.0053

426.3 (3 sig figs) 426

1890(1 sig fig) 2000

0.0296(2 sig figs) 0.030

Rules

for

Multiplication and Division

• Count digits to the right of the decimal.
• Roundthe answer to match the value with the LEASTnumber of decimal places.

12.0 + 131.59 + 0.2798 = 143.8698

least number of decimal places

Multiply or divide

• Answer isrounded to contain the same number of sig figs as the value with the LEAST.

51.3 × 13.75 = 705.375

The answer, with significant figures, is 705.

DO NOT round for each calculation.

When performing multiple calculations, use the rule of the final calculation to round the answer.

(0.3012 + 0.2)(3.6) = ?

(0.5)(3.6) = 1.8

= 2

(0.5012)(3.6) = 1.80432

= 1.8