1. 1.3 Reporting with Precision and Accuracy
Why is the first zero in the number not a significant digit?

2. Today’s Targets I will be able to
Determine the most precise measurement
Calculate with significant digits

3. You ask two friends for the time
You ask two friends for the time. Noah says “about 2:30” and Mia says “2:28 and 19 seconds”. Who is more precise?

4. Precision: the level of detail that an instrument can measure. a
Precision: the level of detail that an instrument can measure. a. If units are different, the smaller unit is more precise. Ex) feet is more precise than yards b. If units are the same, the number with more decimal places is more precise. Ex) feet is more precise than 2.1 feet

5. Question…
What is more precise
2.1 feet or 2.13 yards ?????

6. Complete the tables on page 27.
Which measurement is more precise? meter OR 9.3 meter yards OR 16 feet cup OR 8 ounces feet OR feet
Complete the tables on page 27.

7. Determining Precision of Calculated Measurements
When measuring to the nearest unit, the actual length could be 0.5 units less or 0.5 units greater because of rounding.
If someone says that they measured piece of paper to the nearest half inch and thought it was 8.5 inches, the actual length could have been from to or
from 8.45 to 8.55 inches.
Turn to page 29 for an example.

8. Accuracy: the closeness of a given measurement or value to the actual measurment or value.
To calculate accuracy:
Compute the absolute value of the diffence between the actual measurement and the given measurement.

9. Complete the information in part C at the top of page 28.

10. Significant Digits: digits that contribute to the precision of the measurement

11. Rules for Significant Digits 1. All nonzero digits sig figs 2. Zeros that are to the right of both the last nonzero digit and the decimal point sig figs 3. Zeros between significant digits sig figs 4. Zeros at the end of a whole number are not significant digits 53, sig figs

12. How many significant digits are there. 1. 4. 500 in 2. 1200 m 3
How many significant digits are there? in m ,040 g hrs

13. Significant digits when calculating… A computation is only as precise as the least precise measurement = OR significant digits

14. Quincy is a tour guide at a museum of science and history
Quincy is a tour guide at a museum of science and history. During a tour of the museum, he tells some visitors about a fossilized dinosaur bone that is on display in the museum. He says, “Twenty years ago, a group of paleontologist donated this dinosaur bone to our museum. At the time, they told us that they had estimated the age of the bone to be approximately 90 million years. So now, the bone is about 90 million and 20 years old.” Evaluate the validity of Quincy’s statement.

15. Tonight’s assignment: Page: 35-38 #1-8 all, 10-14 even, 15-18 all, 20, 22, 23