Thinking in Steps
Following a flowchart
Trace a flowchart from start to stop, take the right arrow out of a decision, and say what it prints.
Following a flowchart is like walking a path. You begin at the oval marked Start, walk along each arrow to the next box, do whatever that box says, and keep going until you reach the oval marked Stop. There is never any choice about where to go next — except at a diamond, where the answer to the question chooses the arrow for you.
At a diamond, answer first
The commonest mistake is to guess which way looks right. Do not. Read the question in the diamond, work out its answer for the number you are actually holding, and only then take the arrow marked Yes or the arrow marked No. If the question says "more than 5" then 5 itself is a No, because five is not more than five.
Worked example
A flowchart reads a number. If it is more than 30, it prints Over. If not, it prints Under. The number read is 30. What does it print?
Hold the number that was read: 30.
The diamond's question is about this number and nothing else.
Try it together
Now follow this one: a flowchart sets a total to 0, then goes round adding 6 to the total, three times over.
Answer with the total after each trip round the loop.
1.The total starts at 0. After the first trip round, what is the total?
Have a go
Have a go on your own. A flowchart reads a number. If the number is less than 8, it prints "Low". If not, it prints "High". The number read is 3. What does the flowchart print?
Ready to practise?
Eight questions on what you have just read. Nothing is timed, and you can play as many times as you like.