Thursday, Oct 9, 2008 - Block 4B

Wrote on board for students to sit next to someone who would help them do a lab a do it well.

Handed back lab reports for Graphing Round Objects Lab.
Went over lab
In particular, problems were with calculating averages a+b+c/3 is not the same as (a+b+c)/3
Also mentioned that we use line graphs and not bar graphs or pie charts because line graphs give us relationships between variables. In this lab, by finding the slope of the line, we found the value of pi.

Mass is the amount of matter in an object. Explained how to use the electronic balance to measure mass. Use the mode button to set the scale to read in grams (g). For a dry, solid object that doesn't crumble, you can zero the balance and then place the object on the scale. Read and record to the nearest 0.1 g. If you do have an object that is wet, or crumbles, then first put a cup on the balance. Zero the balance with the cup on it and then add the material to the cup.

Explained how to find the volume of a rectangular solid: V = Length * width * height
You do NOT average the length, width, height. Not only do you multiply the numbers, you also multiply the units. cm3 with the superscript 3 is shorthand for cm * cm * cm
Showed how to measure length, width, and height.

Led students to making a data table. Showed what belonged in the data table. Passed out graph paper and had them use a ruler to line the data table on the back.

Explained how to make the graph. Plot mass (g) on the y axis and volume (cm3) on the x-axis. Assigned lab boxes to each group and let them do the lab.

Most students did a very nice graph and handed them in by the end of the period.