10/24/15
In this lesson I understood pretty well because I read the section in the book the night before. We talked about accuracy and how that is the proximity of a measurement to the true value of a quantity. However precision is different by that it's the proximity of several measurements to each other. Think of it as a dart board with the red bulls eye in the middle of it. Accuracy would be throwing one dart and either hitting super close to the bulls eye or hitting the bulls eye. Precision is throwing 5 darts and hitting the bulls eye each single time.
We also talked about scientific notation. If it had a negative exponent we would move the decimal to the left, but it the number had a positive exponent, you would move the decimal to the right. An example is 0.0803 which would turn into 8.03 x 10(-2 exponent). 3.45 x 10(6 exponent) would turn into 3,450,000.
Significant figures refers to digits that were measured. It's important to know you can estimate 1 digit past the calibrated number!!! Ex. If it was 1.23 you can measure to 1.22 or 1.24 but not to 1.21 or 1.25.
So what zeros counts and don't count as a significant number? Well I'm glad you asked!
Significant numbers and zeros practice!
13 = 2 sf and 0 zs
0.01040 = 4 sf and 2 zs
90 = 1 sf
90.0 = 3 sf
Adding/Subtracting SF:
The rule is you must use the number with the smallest number of decimal places as the limiting term
for rounding. Ex. 4.60 + 3 = 8.6 but 3 has zeros decimal places (limiting term) so it becomes 8
Multiplication and Dividing SF:
The rule is you must use the number with the smallest number of significant figures.
Ex. 2.5 x 0.568 = 1.42 but 2.5 has 2 significant figures while 0.568 has 3. So 1.42 rounds to 1.4.
Measurement conversions!!!
King Kilo = 1,00
Hector Hecto = 100
Died Deka = 10
Drinking Deci = 0.1
Chocolate Centi = 0.01
Milk Milli = 0.001
Micro = 1x106
Nano = 1x109
Pico = 1x1012
Here are some helpful links!
