Your report contains the history of what happened in the laboratory. The emphasis is on what you actually did, rather than on what you were supposed to do. You learn from your mistakes as well as your successes. Here you should include tables of the data you gathered, and tables of intermediate and final values. Graphs showing relationships between the data may also be appropriate.
Most reports require an analysis of the error in the final values obtained.
Detailed calculations should be given in an appendix at the end of the report. In this section you restate the results of your experiment, and quote the error you calculated for your result. At this point you should repeat any important points about the experiment, describe unusual problems encountered, give ways of improving the experiment, and sources of errors in the results. Always give the reasons for your conclusions. Also acknowledge any help received from other persons in writing your report or in working in the laboratory.