Interpreting and communicating [ S2.2 Support Plenary] Weights of diamonds are measured in carats. This table, using information taken from the Internet, gives of prices of round, medium quality diamonds of different weights. Put the information on a suitable chart. Use it to estimate the cost of a 0.6 carat round diamond of medium quality. Preamble If at all possible, pupils should be given the opportunity to experiment with different scales – a useful skill even with computer-aided graph plotting. A number of pupils may need guiding towards using a scatter graph. The activity may be suitable for a whole group to work on with the caveat that as many pupils as possible can contribute to the general discussion. Possible content Selecting appropriate scales and drawing and interpreting scatter graphs. Resources Graph paper. Solution/Notes The scatter graph (based on real data) is obviously non-linear (but it is not expected that pupils will use such formal language). Nevertheless, a cost of about £1400 for a 0.6 carat diamond would be reasonable. Depending on circumstances, the obvious curved nature could be a useful focus of discussion – bigger diamonds are proportionally more expensive. Original Material © Cambridge University Press 2010 Original Material © Cambridge University Press 2010