The big ideaA flowchart is a map of a program. Ovals start and end, boxes act, diamonds ask.
How it works
A flowchart is a map of a program, drawn before you build it. Its arrows show which way to go.
Each step sits in a shape. An oval means start or end, a box means do something, and a diamond asks a yes or no question.
A diamond has two arrows, a yes arrow and a no arrow. The answer picks the way to go.
Drawing first helps you spot mistakes while they are still easy to fix.
The shapes of a flowchart.
Example 1: Choosing a shape
Mina's step is put on the raincoat.
Putting on a coat is something to do, so it goes in a box.
The step is it raining? asks a question, so it goes in a diamond.
Example 2: A rainy day
Bo follows the chart: Start, look outside, then the diamond is it raining?
It is raining, so he takes the yes arrow to the raincoat box.
Both paths meet at walk to the bus, and then comes the end oval.
The rainy-day path is on lines 3, 4, 6 and 7.
Example 3: A sunny day
The next week is sunny, so the answer to is it raining? is no.
Bo takes the no arrow and wears the sunhat.
He goes through 3 boxes: look outside, put on the sunhat and walk to the bus.
One chart works for both days.
Example 4: Two questions
A chart asks is it raining? and then asks is the bus here?
Each question gets its own diamond, so the chart has 2 diamonds.
Words to know
flowchart
A map of a program, drawn before you build it.
oval
The shape for start or end.
box
The shape for do something.
diamond
The shape that asks a yes or no question.
arrow
Shows which way to go next.
Watch out
A question never goes in a box. It needs a diamond with a yes arrow and a no arrow.
An action, like put on the raincoat, goes in a box, not a diamond.
Check where the two paths meet again, so the chart carries on from one box.
Draw the chart first, before you build the program.
Try it
Which shape does the step Is the door open? go in?
Which shape does the step Pour the milk go in?
Which shape does the step End go in?
How many arrows come out of a diamond?
True or false: you draw the flowchart after you build the program.
Answers: 1. A diamond · 2. A box · 3. An oval · 4. 2 · 5. False
Try at homeWith a grown-up, draw a flowchart for deciding what to wear, or what to do after school. Use an oval for the start and the end, boxes for actions and a diamond for each yes or no question, then follow it with your finger, like Bo did.
For grown-upsDo the Mission: draw a flowchart together for deciding what to wear or what to do after school. Use an oval for the start and the end, boxes for actions and a diamond for each yes or no question, then follow it with a finger.
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