Bar chart and pictogram maker for the classroom

What the chart maker does on screen

One chart across the board with an editable table underneath it, so the numbers and the picture are always on screen together. Every change lands straight away, which means you can argue with the class about a bar while you are moving it.

• The data table. One row per category: a colour square, a name box, minus and plus either side of the number, and a cross to delete the row. Type in either box, or tap minus and plus, and the chart changes as you go. The add button names what it adds, so it says Row on a pictogram and Slice on a pie. Tap a colour square to give that row a different colour. Twelve rows is the most.
• Drag any chart. A bar or a line point up and down, a pictogram row sideways to add and take away squares, and a pie slice round by its edge. Drag one slice and only that number changes, so every other share moves because the whole has changed.
• Four chart types from the same table. The pie labels each slice with its percentage and lists every category with its count.
• Title and axes. Three boxes, starting on a worked example about favourite fruit. Type straight over them.
• The black bar at the foot. Values, Gridlines, Table and Copy table. Values prints the number above each bar, beside each pictogram row and inside each pie slice, and turning it off is how you make the class read the scale. Table hides the rows for a clean board, and the chart grows to fill the space.
• Max and Step. Blank means the chart picks its own scale. Type a Max for the top of the axis and a Step for the gap between labelled lines. The axis always starts at zero.
• Key. On the pictogram, what one square is worth, printed on a sample square at the foot of the chart. A number that does not divide exactly leaves a part-filled square.
• Random, Copy table, Reset and Print. Random gives every row a fresh number for a starter. Copy table puts the names and numbers on the clipboard, tab separated, so they paste straight into a spreadsheet. Reset puts back the starting data. Print gives you one A4 landscape sheet of the chart as it stands.

How to use it in a lesson

Collect the data first, by hands up or by tally, and get the categories typed in before any numbers go near the board. The drawing is the quick part, so the lesson time goes on reading and arguing rather than ruling axes.

1. Type the categories, then count. Five or six is plenty. Take one at a time and watch the bar grow as you type.
2. Set the scale on purpose. A Step of 2 or 5 makes children read a bar finishing between two labelled lines, and that is what separates drawing a chart from reading one.
3. Turn Values off before you ask anything, then ask for the height of each bar and put them back on to check.
4. Switch chart type with the same numbers up. Which answers "how many more" quickest, and which answers "what share"?
5. Change one number live. Drag a bar up, and before you switch to the pie, ask what will happen to every other slice. Most expect only one to move. On the pie itself, dragging one slice bigger shows it: nobody else's number changed, but everybody else's share did.
6. Print the finished chart if it is worth sticking in books, then Reset and start again.

Ideas by year group

• Year 1. Pictogram, Key 1, four categories. Count the squares together. Which row has most, which has fewest?
• Year 2. Bar, Values off, Step 2. This bar stops between 6 and 8. What is it, and how do you know it is not seven and a half?
• Year 3. Pictogram, Key 5. One square is five children, so how many is three and a half squares? Then set the Key to 10 and ask again.
• Year 4. Bar, Step 10, one very tall bar. Add a category worth 3 and ask if this scale is still fair to it.
• Year 5. Pie, Values on. A slice says 25 per cent, so how many children is that? Switch to Bar to find out.
• Year 6. Line, fruit categories still in place. Does joining these points mean anything? What would the x-axis have to be?

The misconceptions it helps with

Counting gridlines instead of reading the scale. Set Step to 5 and a child who has only met charts labelled in ones will call a bar of 15 a three. Dragging that bar while the number in the table moves fixes the link between height and value in seconds.

Treating every pictogram symbol as one. With Key set to 5, three squares is fifteen. The sample square at the foot of the chart is the thing to point at every single time, before anybody counts.

Reading a percentage as a count. A slice labelled 20 per cent is not twenty children. Switch to the bar chart, find the real number, then switch back. Share and amount stop being the same word.

Joining points that should not be joined. The line graph will cheerfully connect apples, bananas and pears. Ask what the line means halfway between two fruits. Nothing, and that is the lesson.

Frequently asked questions