Structure diagram

Name:

Date:

Class:

Quick Questions

Shade in the A or B circle for each question.

1. Which box sits at the very top of a structure diagram?

A A box naming the whole problem

B A box naming the last step to be done

2. What do the lines in a structure diagram do?

A Show the order in which steps run

B Join a box to its sub-boxes below it

3. A structure diagram for a school library system has the top box 'Library system'. Which is a sensible box on the level below?

A Issue a book

B Library system

4. Boxes 'Enter marks' and 'Print report' are both directly under 'Marks system'. What does this tell you?

A They are on the same level

B 'Print report' is a sub-problem of 'Enter marks'

5. Does a structure diagram show the order in which the steps happen?

A Yes, boxes are read left to right as a sequence

B No, it shows the parts of the problem

Match the Pairs

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

Left column		Right column
1Top box: Library System		AQuiz Game → Ask Question, Check Answer, Show Score
2Library System → Borrow Book, Return Book		BThe top box of a structure diagram names the whole problem that is being broken down.
3Boxes at the same level are sub-problems of equal rank, each joined by a line to the same parent box		CThis shows a sequence of steps with arrows, which is a flowchart. A structure diagram shows the parts in levels joined by lines, not the order of the steps.
4A structure diagram shows the parts of a problem, not the order in which the steps happen		DLines join a box to its sub-boxes. Borrow Book and Return Book sit on the same level, below the whole problem.
5Level 1: Quiz Game. Level 2: Ask Question, Check Answer. Top box: Ask Question		ELevel 1: Input Marks \| Calculate Grade \| Print Report (left to right does not mean first to last)
6Start → Input Marks → Calculate Grade → Print Report → End (drawn as a structure diagram)		FThe top box must name the whole problem, Quiz Game, not one of the sub-problems such as Ask Question.

Definitions

structure diagram

Fill in the Blanks

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

Level _: Quiz Game Level 2: Ask Questions, Mark Answers

The top box names the _____ problem

_____ join a box to its sub-boxes

A structure diagram shows the _____ , not the order

Ask Questions and Mark Answers: ____ level

Spot the Error

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

Question 1

A L0: Check stock

B L1: Record sales

C L1: Check stock

D L1: Print receipts

Question 2

A L0: Make a weather app

B L1: Get the data

C L2: Work out averages

D L1: Show the forecast

Question 3

A L0: Plan a party

B L1: Step 1 - Choose the food

C L1: Send invitations

Question 4

A L0: Library system

B L1: Manage books

C L3: Add a new book

D L2: Remove a book

E L1: Manage members

Question 5

A L0: Cafe ordering system

B L1: IF drink THEN take order

C L1: Work out the bill

D L1: Take payment

Answer Key

Structure diagram

Section A: Quick Questions

A — A box naming the whole problem

B — Join a box to its sub-boxes below it

A — Issue a book

A — They are on the same level

B — No, it shows the parts of the problem

Section B: Match the Pairs

Top box: Library System → The top box of a structure diagram names the whole problem that is being broken down.

Library System → Borrow Book, Return Book → Lines join a box to its sub-boxes. Borrow Book and Return Book sit on the same level, below the whole problem.

Boxes at the same level are sub-problems of equal rank, each joined by a line to the same parent box → Quiz Game → Ask Question, Check Answer, Show Score

A structure diagram shows the parts of a problem, not the order in which the steps happen → Level 1: Input Marks | Calculate Grade | Print Report (left to right does not mean first to last)

Level 1: Quiz Game. Level 2: Ask Question, Check Answer. Top box: Ask Question → The top box must name the whole problem, Quiz Game, not one of the sub-problems such as Ask Question.

Start → Input Marks → Calculate Grade → Print Report → End (drawn as a structure diagram) → This shows a sequence of steps with arrows, which is a flowchart. A structure diagram shows the parts in levels joined by lines, not the order of the steps.

Section C: Definitions

structure diagram — A diagram with the whole problem in a top box, joined by lines to lower boxes for each sub-problem, in levels. It shows the parts of the problem, not the order of the steps.

Section D: Fill in the Blanks

Level 1: Quiz Game
Level 2: Ask Questions, Mark Answers

The top box names the whole problem

Lines join a box to its sub-boxes

A structure diagram shows the parts
, not the order

Ask Questions and Mark Answers: same level

Section E: Spot the Error

A — The top box must name the whole problem, not just one part of it. Line 1 should be 'L0: Run a school shop'. 'Check stock' is a sub-problem and belongs at level 1.

C — 'Work out averages' is a sub-problem of the whole app, so it sits at the same level as the other boxes under the top box. It should be 'L1: Work out averages', not level 2.

B — A structure diagram shows the parts of the problem, not the order of the steps. Box names should not have step numbers. It should be 'L1: Choose the food'.

C — 'Add a new book' is a sub-box of 'Manage books' (level 1), so it is level 2. Levels cannot be skipped. A line joins a box to the level directly below it.

B — Boxes in a structure diagram only name sub-problems. Decisions such as IF ... THEN belong in a flowchart or pseudocode. It should be 'L1: Take the order'.