Biodiversity Percentages

Two sites with different total counts cannot be compared by raw numbers. Percentages fix that, and discovering why is the lesson.

We give them counts that look conclusive and are not, then let them work out that the sample sizes differed. The correction is theirs rather than ours.

The page has the conversion frames, two data sets, and a comparison. It also introduces the idea of a dominant species, which is when one thing accounts for most of the count and the site is less diverse than the total suggests. Grade five gets this quickly and it changes how they read every number afterwards.