Calculations - Rules & Advice
When writing a lab report, keep in mind that you want to report what you did
as clearly as possible. The General Lab Rubric describes all the sections and
the order in which they should appear, but this page is a more detailed description
of how to present calculations.
- First of all, don't be afraid to take up lots of room. Make them super easy
to read by spreading them out.
- Don't be afraid to type them, but calculations are often easier for a student
to present well by hand. If you decide to type them, use of decimal-aligned
tabs or courrier font can help presentation.
- ALWAYS describe what you are doing in words or equations.
One way is to use descriptive sentences in two columns (click
here for an example). I will be expecting a specific format that should
serve you well in any class you take; but of course your current teachers'
preferences should always be respected. Here are my preferences
- additions and subtractions should always be "stacked"
and each line should include the description and label of the number too
mass of beaker and gall bladder 373.96 g
- mass of beaker - 126.11 g
= mass of gall
- multiplication and division should always be shown
like multiplying fractions:
D = m = 23.16
g = 4.1 g
V 5.7 mL
q = mDTCp = (23.16 g)(6.6 C)(0.84
cal) = 130 cal
- Notice that besides every number having a label (like "g") and
a name (like "mass of ..." or "V"), the decimal points
are lined up whenever possible, and the answers are reported with the proper
number of significant figures.
- If you have a lot of calculations that are the same, you only need to show
the first set in detail as a sample calculation. For the
rest, just summarize the results. For example, if you have to calculate 10
different densities in the same way, just show the first one (as above), then
present all ten in a results table.
- Finally, if you ever have any questions, ask yourself this: is it completely
clear and completely correct? Because you should ask your teacher
if you have any questions, and your teacher will answer with those two thoughts
If you decide to type your lab reports, I have written a lab without any content
and put it on the web site at zahm.org/mhs/common/sample.doc.
It is a Word 2000 document that has all the general sections of a lab formatted,
including the calculations section. Try it out!
[Send Me Suggestions][MHS
Chem page][MHS AP Chem page]