Answers

F5.2 Flowcharts

Algorithms · GCSE · OCR J277 2.1.2, AQA 8525 3.1.1, Edexcel 1CP2 1.2.1 · about 15 min

What this lesson is about

The standard symbols, and turning a flowchart into code.

• The symbols
• From flowchart to code
• A loop that counts
• Drawing your own

Questions 5 marks in all

1. [1 mark]Which flowchart symbol is used for a decision?

   1. AA diamond
   2. BA rectangle
   3. CA rounded box
   4. DA slanted box
   Answer: A. A decision is a diamond with a Yes arrow and a No arrow.

2. [1 mark]Which symbol is used for input or output?

   1. AA slanted box (parallelogram)
   2. BA diamond
   3. CA rectangle
   4. DA box with double sides
   Answer: A. Inputs and outputs use a parallelogram.

3. [1 mark]In a flowchart, an arrow goes back up to an earlier decision. What does that become in code?

   1. AA while loop
   2. BAn if with no loop
   3. CA function
   4. DA comment
   Answer: A. Looping back to a decision repeats while the answer allows: a while loop.

4. [1 mark]What is the box with double lines on its sides for?

   1. AA subroutine defined elsewhere
   2. BA decision
   3. CThe start of the flowchart
   4. DA variable
   Answer: A. It calls a subprogram, such as tone(note, 0.2).

5. [1 mark]The rising scale flowchart starts with count = 0 and loops while count < 5, adding 1 each time. How many notes does it play?

   Answer: 5. count takes the values 0, 1, 2, 3 and 4 while the loop runs.

The task: the password guard

# the two lines every program starts with: the commands, then the robot
from bugbot import *
connect()

password = input("Password? ")

from bugbot import *
connect()
password = input("Password? ")
while password != "bugbot":
    print("wrong")
    tone(220, 0.3)
    password = input("Password? ")
led("green")
forward(50, distance=20)