Data starts as a question and a heap of answers. This unit follows the whole path: what kind of data it is, how to ask and whom to ask so the numbers can be trusted, how a tally and a frequency table turn a list into something readable, and how to draw it as bars, a histogram, a pie or a line. It finishes with the harder skill: choosing the chart that fits and noticing when a chart gives a false picture of numbers that are all correct.
Every idea is something you can move: send a variable down two questions, test answer boxes for gaps, tally a list one value at a time, change the scale of a bar chart, cut a circle from a table, plot a line week by week, and slide the start of an axis to watch a small difference grow. No calculator is needed anywhere in this unit.
The lessons, in order
- Lesson 1 · Types of data Categorical data (nominal and ordinal) and numerical data (discrete and continuous), and what each type lets you do. Send nine variables down two questions to name their type, then make a clock finer and watch a measurement gain values that a count never has. No calculator
- Lesson 2 · Asking and collecting Primary and secondary data, fair and unbiased survey questions, answer options that cover everyone exactly once, and a sample used to estimate a whole group. Test four sets of answer boxes against every number of hours, then compare three samples of the same 30 students with the whole group. No calculator
- Lesson 3 · Tally and frequency tables Tally marks, frequency tables for single values, total frequency, and grouped frequency tables with equal-width classes. Tally 24 values one at a time and watch the pattern appear, then group 20 heights into classes of width 2, 4 or 8. No calculator
- Lesson 4 · Bar charts and histograms Bar charts for categories and counts, choosing a scale with gridlines, reading a bar, and histograms with touching bars for grouped measurements. Redraw a bar chart with gridlines every 2, 5 or 10, then draw grouped plant heights as touching bars of widths 2, 4 and 8. No calculator
- Lesson 5 · Pie charts Pie charts: sector angle from a frequency and a total, from a percentage, angles adding to 360 degrees, and pies comparing proportions not counts. Draw six pies from tables with totals that divide 360, then draw a sector from any percentage in steps of 5%. No calculator
- Lesson 6 · Line graphs Line graphs for measurements over time, reading steepness as rate of change, reading between plotted points, and a prediction past the end. Plot a bamboo shoot's height week by week, then read a value between two weeks and extend the line to a prediction. No calculator
- Lesson 7 · Choosing and honest charts Choosing a chart from the type of data and the question, and spotting a chart that misleads by an axis that does not start at zero, an uneven scale or the wrong type. Move the start of a bar chart's axis and compare how tall a bar looks with how large it is, then send seven situations through three questions to pick the chart. No calculator
Every lesson has a teacher page with the answers, the misconceptions each wrong answer reveals, discussion questions, differentiation and support for students learning in English, and extra questions in three tiers.