Building a flowchart from a problem

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Quick Questions

Shade in the A or B circle for each question.

1. A problem says: 'Read two numbers and output their sum.' What should you do FIRST when building the flowchart?

A List the inputs, processes and outputs

B Draw the Stop symbol and work backwards

2. Which is the correct order for the symbols in a flowchart that reads a mark and outputs it?

A Input parallelogram, Start, Stop, output parallelogram

B Start, input parallelogram, output parallelogram, Stop

3. A problem says: 'Keep asking for a password until it is correct.' What does this wording tell you?

A There is a repeated step, so a loop is needed

B There is only a sequence, so no loop is needed

4. A problem says: 'If the temperature is above 30, output Hot, otherwise output Not hot.' Which symbol shows this choice?

A A rectangle process box with two outputs

B A diamond decision with Yes and No branches

5. Your flowchart has a decision diamond. The Yes branch leads to Stop but the No branch ends in mid-air. What is wrong?

A Not every path reaches Stop

B Nothing, only the Yes path needs to reach Stop

Match the Pairs

Draw a line connecting each item on the left to its match on the right.

Left column		Right column
1Inputs: length, width \| Process: area ← length * width \| Output: area		AThe No path from the decision never reaches Stop, so the flowchart has a dead end. Every path must lead to Stop.
2Start → Input → Process → Output → Stop		BThe order of symbols in a flowchart with no decisions or loops: begin at Start, end at Stop, and use the correct shape for each step
3Identify a decision: the problem says to do different things depending on a condition, so draw a diamond with Yes and No paths		CCount < 10 ? Yes: INPUT Mark, Count ← Count + 1, back to the test / No: go on to Stop
4Identify repeated steps: the problem says to do something many times, so draw a flow line that loops back to an earlier step		DThe first planning step: list the inputs, processes and outputs of the problem before drawing any symbols
5Start → Input Mark → Mark >= 50 ? → Yes: Output "Pass" → Stop (the No path has no flow line)		EMark >= 50 ? Yes: OUTPUT "Pass" / No: OUTPUT "Fail"
6Start → Process: INPUT Mark → Process: OUTPUT Mark → Stop		FThe wrong symbols are used: INPUT and OUTPUT must be in parallelograms, not process rectangles.

Definitions

Start to Stop

Fill in the Blanks

Complete each line of code by filling in the missing parts.

Start -> INPUT Age -> OUTPUT Age -> ____

Decision: Mark __ 50 ? Yes -> OUTPUT "Pass" No -> OUTPUT "Fail"

Input: Price, Qty _______: Total ← Price * Qty Output: Total

Count ← 0 WHILE Count < 5 DO Count ← Count _ 1

Test value: Mark = 70 Mark >= 50 is ____ Output: Pass

Spot the Error

Shade in the letter of the line that contains an error.

Question 1

A Oval: Start

B Rectangle: INPUT Num

C Rectangle: Result ← Num * 2

D Parallelogram: OUTPUT Result

E Oval: Stop

Question 2

A Oval: Start

B Parallelogram: INPUT Mark

C Diamond: Mark >= 50 ?

D Yes: line to OUTPUT Fail

E No: line to OUTPUT Fail

F Both lines go to Oval: Stop

Question 3

A Oval: Start

B Rectangle: Total = 0

C Parallelogram: INPUT Num

D Rectangle: Total ← Total + Num

E Parallelogram: OUTPUT Total

F Oval: Stop

Question 4

A Oval: Start

B Parallelogram: INPUT Pass

C Diamond: Pass ← "cat" ?

D No: line back to INPUT Pass

E Yes: line to Oval: Stop

Question 5

A Rectangle: Start

B Parallelogram: INPUT Age

C Diamond: Age >= 16 ?

D Yes: line to OUTPUT Allowed

E Oval: Stop

Answer Key

Building a flowchart from a problem

Section A: Quick Questions

A — List the inputs, processes and outputs

B — Start, input parallelogram, output parallelogram, Stop

A — There is a repeated step, so a loop is needed

B — A diamond decision with Yes and No branches

A — Not every path reaches Stop

Section B: Match the Pairs

Inputs: length, width | Process: area ← length * width | Output: area → The first planning step: list the inputs, processes and outputs of the problem before drawing any symbols

Start → Input → Process → Output → Stop → The order of symbols in a flowchart with no decisions or loops: begin at Start, end at Stop, and use the correct shape for each step

Identify a decision: the problem says to do different things depending on a condition, so draw a diamond with Yes and No paths → Mark >= 50 ? Yes: OUTPUT "Pass" / No: OUTPUT "Fail"

Identify repeated steps: the problem says to do something many times, so draw a flow line that loops back to an earlier step → Count < 10 ? Yes: INPUT Mark, Count ← Count + 1, back to the test / No: go on to Stop

Start → Input Mark → Mark >= 50 ? → Yes: Output "Pass" → Stop (the No path has no flow line) → The No path from the decision never reaches Stop, so the flowchart has a dead end. Every path must lead to Stop.

Start → Process: INPUT Mark → Process: OUTPUT Mark → Stop → The wrong symbols are used: INPUT and OUTPUT must be in parallelograms, not process rectangles.

Section C: Definitions

Start to Stop — List the inputs, processes and outputs, then draw Start, the steps in order with the correct symbols, and Stop. Check every path reaches Stop, then trace it with test values.

Section D: Fill in the Blanks

Start -> INPUT Age -> OUTPUT Age -> Stop

Decision: Mark >= 50 ?
Yes -> OUTPUT "Pass"
No -> OUTPUT "Fail"

Input: Price, Qty
Process: Total ← Price * Qty
Output: Total

Count ← 0
WHILE Count < 5 DO
   Count ← Count + 1

Test value: Mark = 70
Mark >= 50 is TRUE
Output: Pass

Section E: Spot the Error

B — Input must be drawn in a parallelogram, not a rectangle. A rectangle is for processes. It should be Parallelogram: INPUT Num.

D — The Yes path is taken when Mark >= 50, so it must lead to OUTPUT Pass. Testing with Mark = 70 would wrongly output Fail.

B — Setting a starting value is an assignment, so it uses ←, not =. It should be Rectangle: Total ← 0 so the total starts at zero.

C — A decision compares values, so it needs the comparison = and not the assignment arrow ←. It should be Diamond: Pass = "cat" ?.

A — Start and Stop use the terminator symbol, which is an oval. A rectangle is a process symbol. It should be Oval: Start.