You already know how to put figures in a spreadsheet table. Today you will turn those figures into a chart, then deliberately break the chart so you can see how the same honest numbers can be made to look dramatic. By the end you will have one honest chart, one misleading twin, and a one-line rule for reading charts you meet online.
A chart is not a neutral picture of numbers. It is an argument. The person who made it chose the type, the scale, the title and where the axis starts. Those choices can make a small difference look huge, or a real difference look tiny, without changing a single figure.
Today's demo data (put these five rows into a new sheet if you need a fresh start):
- Messaging: 50 minutes
- Short video: 60 minutes
- Games: 45 minutes
- School apps: 40 minutes
- Music: 42 minutes
If two charts show the exact same numbers, how can one of them still mislead you?
Follow the walkthrough on your device in Excel or Google Sheets. Read only the path for the tool you use.
Use the five demo rows shown here for this walkthrough. You will build charts from your own figures (or a quick reuse of these) in the next activity.
First: the totals and an honest chart, axis at zero.
Work through formulas, insert a column chart, title it, and lock the vertical axis at zero. Check that the bars look close together.
Then: break it on purpose, axis at 35.
Change only the axis start to 35. Watch Short video leap and School apps shrink. No figure changed.
If your chart looks wrong (one bar only, or it says Series1), click inside the data block A1:B6 and Insert Chart again.
Make a misleading twin of the chart you just built, then name the trick in one sentence.
The figures are printed on the bars, so you can check them: they are identical in both charts. On the left the axis starts at 0, and the bars sit close together because the numbers are close together. On the right it starts at 35, and the Short video bar becomes five times the height of School apps — for a real difference of twenty minutes out of sixty.
- Duplicate the honest chart, keeping every number identical.
Excel: click the chart edge, Ctrl+C then Ctrl+V, and drag the copy beside the first.
Sheets: click the chart, Ctrl+C then Ctrl+V. - On the copy only, set the vertical axis to start at 35 instead of 0.
- Write one sentence under the pair naming the trick. For example: “The second chart starts its axis at 35, so a small gap looks like a huge lead.”
Reuse the demo numbers with new category names and change only the axis and the sentence. That still counts.
Pull out what just happened. The misleading chart did not invent a number. It changed the frame: where the axis starts, how tall the plot area makes a gap look, and sometimes what the title claims. That is the same habit you use when you evaluate a source: ask not only "are the facts right?" but "is the presentation fair?"
When you meet a chart online, check the axis start, the scale, and whether the title matches what the bars actually show, before you trust the story it is selling.
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