Bar charts are one of the most effective ways of conveying quantitative data, be it size of population, GDPs or life expectancy. However, while they’re excellent for comparing values, they don’t really convey the size of the values.

For example, if a bar is representing a population of 5 million people or of just a small group of people it’s still just a rectangle. There’s no indication (besides the y-axis) that a bar is representing 10, 100, 1000 or 10,000 individual items.

To address this, you can split a bar into smaller cells.