Cornell Notes 1.5 - Using Math and Statistics in Science
September 28, 2015 -Pages 31 and 33
• You will make a lot of measurements and calculations using measurements in this class.
• Remember this – all measurements have units. How else would we know what we’re measuring?
• Any measurement you make without a unit will be considered wrong in this class
• Precision is the word scientists use to indicate how small the units their instruments can measure.
• For example on your ruler, there are ten marks between each centimeter, so the precision is 0.1 cm.
• In science, you’ll have to round your calculations.
• The rule is round to the same precision you measure!
• When you make many measurements of the same thing you will notice that the values cluster around an average.
• To calculate an average, add up all the measurements and divide by the total number of measurements.
• Round to the precision you measure!
• Your average will always be less than or equal to your largest data point.
• And greater than or equal to your smallest data point.
• In science, the word accuracy means how close a measurement is to the true value of what is being measured.
• Error is the difference between a measurement and the true value of what is measured.
• To figure out error, do these three steps
1. Subtract your average from your highest result (maximum).
2. Subtract your lowest result (minimum) from your average
3. Pick the bigger of the two answers
4. Put a ± sign in front
• In your experiments, you want to be as accurate as possible, which means you want error to be low
• In science, it is always important to determine changes in your results
• To find change, simply subtract one average from another.
• In science, two measurements are considered the same if their difference is less than or equal to the amount of error.
• In science, we say that two variables could be related if changing one causes a significant change in the other.
• A significant change is one in that the change caused by changing the variable is greater than the average error
• In other words, changing does more than boo-boos do…