You already have a frequency table from your survey. A column of numbers is accurate, but it is hard to spot the biggest option or the share of the whole at a glance.
Today you turn that table into two charts: a bar chart for comparing categories, and a pie chart for showing parts of a whole. By the end you will have both on paper for your portfolio, and you will be able to say which chart fits which kind of question.
Same survey, two charts. The bar chart makes it easy to see which category is tallest. The pie chart makes it easy to see each category’s share of the full set of responses.
| Concept | Why it matters | Example |
|---|---|---|
| Bar chart — one bar per category; height shows the count | Best for comparing options side by side (which got more?) | Housing 9 vs Transport 6 is obvious from the bar heights |
| Pie chart — slice angle = count ÷ total × 360° | Best for showing parts of one whole (what share?) | 9 out of 24 is 135°, just over a third of the pie |
| Choosing the chart — match the chart to the question | The wrong chart hides the finding you care about | “Who won?” → bar; “What share chose housing?” → pie |
Worked class data for today (24 responses to “Which local issue should the council prioritise?”):
Open the bar-chart builder. Set one bar for each category from the worked class data, and match the heights to the frequency table:
Drag each bar until it hits the right value on the scale. Check that the tallest bar is Housing and that Waste is the shortest. If your own survey has different categories and counts, rebuild the chart with your numbers instead once you have matched the worked example.
Now show the same survey as parts of a whole. In the pie-chart builder, set each category count to match the frequency table (or your own survey totals):
Watch the slices grow as the counts change. Turn on percentages and degrees if they are available, and check Housing is just over a third of the pie (9 ÷ 24 = 37.5%, which is 135°). Compare the pie with the bar chart: which one answers “who won?” faster, and which one answers “what share chose housing?” faster?
Your charts only count as portfolio evidence when they are drawn up so someone else can read them. On a fresh page in your Maths Portfolio, record the frequency totals you used, sketch both charts, and finish with a sentence that says which chart you would publish and why.
Instructions: Fill every row. Show the working for any percentage or angle you calculate. Sketch the bar chart and the pie chart leaving room under each heading for your answer, label the axes or slices, and answer the interpretation prompt in a full sentence.
Work each row in order onto a fresh page in your Maths Portfolio. Show the working, not just the answer.
Write these down the page, leaving room under each for your answer:
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