Computing Science Department
Douglas Academy
Software Design and Development
Computational Thinking
Learning Outcome 1
Name:
Version 4
Task 1: The PRINT command
1. Explain the purpose of the PRINT command in a True Basic program.
Example Question
Explain the purpose of the following code.
Line 1
PRINT “Douglas Academy”
Line 2
PRINT “Craigton Road”
Line 3
PRINT “Milngavie”
Line 4
PRINT “Glasgow”
Line 5
PRINT “G62 7HS”
Line 6
END
Answer
This program will display the following text on the screen.
Douglas Academy
Craigton Road
Milngavie
Glasgow
G62 7HS
Douglas Academy
Computing Science Dept
Computational Thinking Booklet V4
2
SDD Unit
2. Explain the purpose of the following code.
Line 1
PRINT “Hello world”
Line 2
PRINT “This is my first computer program!”
Line 3
PRINT “I think I am going to love programming”
Line 4
END
Answer
Douglas Academy
Computing Science Dept
Computational Thinking Booklet V4
3
SDD Unit
Task 2: The INPUT command
1.
Explain the purpose of the INPUT command in a True Basic program.
Example Question
Explain the purpose of the following code.
Line 1
PRINT “Please enter your name”
Line 2
INPUT name$
Line 3
PRINT “Hello”;name$
Line 4
PRINT “Welcome to Computing Science”
Line 5
END
Answer
This program will ask the user for their name and then display their name in a welcome
message.
Douglas Academy
Computing Science Dept
Computational Thinking Booklet V4
4
SDD Unit
2. Explain the purpose of the following code.
Line 1
PRINT “Please enter your favourite country”
Line 2
INPUT country$
Line 3
PRINT “I know”
Line 4
PRINT country$
Line 5
PRINT “It is a beautiful place to visit”
Line 5
END
Answer
Douglas Academy
Computing Science Dept
Computational Thinking Booklet V4
5
SDD Unit
Task 3: Variables
In True Basic data is stored in variables. Data can be numbers or text. If numbers are
being stored these are known as either Integer variables, if it a whole number e.g. 1, 2,
3, or Real variables, if the number has a decimal point e.g. 1.1, 2.2, 3.3.
If text is being stored it is known as a String variable. If text is being stored then the
String variable name ends with a dollar ($) sign.
Look at the following code
Line 1
PRINT “Please enter your name.”
Line 2
INPUT name$
Line 3
Print “Please enter your age.”
Line 4
Input age
Line 5
END
Choose from the following options the type of data that will be stored in the variable
name$ in line 2.
A. Integer, B. Real,
C. String
Choose from the following options the type of data that will be stored in the variable
age in line 4?
Douglas Academy
Computing Science Dept
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SDD Unit
A. Real,
B. Integer, C. String
Task 4: String variables and the LET command
1. Explain the purpose of the LET command in a True Basic program.
2. Read the following lines of True Basic and describe what each line does. The first
one has been completed for you.
LET day$ = “Tuesday”
Answer
This will assign the value Tuesday to the string variable day$
LET team$ = “Partick Thistle”
Answer
LET month$ = “December”
Answer
Douglas Academy
Computing Science Dept
Computational Thinking Booklet V4
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SDD Unit
Task 5: Numeric Variables
1 Read the following lines of True Basic and describe what each line does.
1)
LET wage = hours_worked * rate_of_pay
Answer
This will multiply the value of hours_worked by the value of
rate_of_pay and assign the result to the numeric variable wage.
2)
LET sum = first_num + second_num
Answer
3)
LET years = months / 12
Answer
Douglas Academy
Computing Science Dept
Computational Thinking Booklet V4
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SDD Unit
Task 6: The FOR ....NEXT construct
1. Explain the purpose of the FOR... NEXT construct.
Example Question
Look at the lines of code below and describe the purpose of the FOR ... NEXT
construct on lines 1 and 7.
Line 1
FOR counter = 1 to 5
Line 2
PRINT “Please enter the pupil’s name”
Line 3
INPUT pupil$
Line 4
PRINT “Please enter the pupil’s mark”
Line 5
INPUT mark
Line 6
PRINT pupil$; “ “;mark
Line 7
NEXT counter
Answer
The FOR ..NEXT construct repeats 5 times. This means the code between lines 2 and 6
will be repeated 5 times.
Douglas Academy
Computing Science Dept
Computational Thinking Booklet V4
9
SDD Unit
2. Look at the lines of code below and describe the purpose of the FOR ... NEXT
construct in lines 1 and 6.
Line 1
FOR counter = 1 TO 10
Line 2
PRINT “Enter name of the item”
Line 3
INPUT item$
Line 4
PRINT “Enter the cost of the item.”
Line 5
INPUT item_cost
Line 6
NEXT counter
Answer
3.
Choose from the following options the type of data that will be stored in the
variable item_cost in line 5?
A. Real,
B. Integer, C. String
Douglas Academy
Computing Science Dept
Computational Thinking Booklet V4
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SDD Unit
3. The code is extended to add another two lines.
Explain what the new two lines will do.
Line 1
FOR counter = 1 TO 10
Line 2
PRINT “Enter name of the item”
Line 3
INPUT item$
Line 4
PRINT “Enter the cost of the item”
Line 5
INPUT item_cost
Line 6
LET total = total + item_cost
Line 7
NEXT counter
Line 8
PRINT “Your total cost is “ ; total
Line 6:
Line 8:
Douglas Academy
Computing Science Dept
Computational Thinking Booklet V4
11
SDD Unit
Task 7: The IF…. THEN … END IF statement
1. Explain the purpose of the IF ... THEN .... END IF construct.
Example Question
Look at the lines of code below and describe the purpose of the
IF .. THEN...END IF construct.
Line 1
Line 2
Line 3
IF points_scored > 1000 THEN
PRINT “Congratulations you are on the leader board”
END IF
Answer
If the value of the numeric variable ‘points_scored’ is greater than 1000 then the
message in line 2 will be displayed
Douglas Academy
Computing Science Dept
Computational Thinking Booklet V4
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SDD Unit
2. Look at the lines of code below and describe the purpose of the
IF .. THEN...END IF construct.
Line 1
IF mark>= 50 THEN
Line 2
Line 3
PRINT “Well done, you’ve passed”
END IF
Answer
3. Look at the lines of code below and describe the purpose of the
IF .. THEN... ELSE construct.
Line 1
IF password$=correct_password$ THEN
Line 2
Line 3
PRINT “Login successful”
ELSE
Line 4
PRINT “Incorrect password.”
Line 5
PRINT ”Please try logging in again”
Line 6
END IF
Answer
Douglas Academy
Computing Science Dept
Computational Thinking Booklet V4
13
SDD Unit
Task 8: The DO.. LOOP UNTIL construct
1. Explain the purpose of the DO.. LOOP UNTIL construct.
Example Question
Look at the lines of code below and describe the purpose of the
DO ... LOOP UNTIL construct.
Line
Line
Line
Line
1
2
3
4
DO
PRINT “What is the capital of Scotland?”
INPUT answer$
LOOP UNTIL answer$= “Edinburgh”
Answer
The DO .. LOOP UNTIL will keep repeating the instructions on lines 2 and 3 until the
user enters “Edinburgh” as the value for the string variable ‘answer$’.
Douglas Academy
Computing Science Dept
Computational Thinking Booklet V4
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SDD Unit
2. Look at the lines of code below and describe the purpose of the DO
... LOOP UNTIL construct.
Please note that <> means not equal to.
Line
Line
Line
Line
Line
Line
Line
1
2
3
4
5
6
7
DO
PRINT “Enter your password”
INPUT password$
IF password$ <> “top secret” THEN
PRINT “Incorrect password. Please try again”
END IF
LOOP UNTIL password$=”top secret”
Answer
Douglas Academy
Computing Science Dept
Computational Thinking Booklet V4
15
SDD Unit
Task 9: Bringing it all together
1. Look at the code below
Line 1
PRINT “Please enter the number of tickets you require”
Line 2
INPUT number_of_tickets
Line 3
FOR counter = 1 TO number_of_tickets
Line 4
PRINT “Enter name of band”
Line 5
INPUT band_name$
Line 6
PRINT “Enter the ticket cost in pounds and pence”
Line 7
INPUT ticket_cost
Line 8
LET total_cost = total_cost + ticket_cost
Line 9
NEXT counter
Line 10
PRINT “The cost of your tickets is “; total_cost
Line 11
END
Douglas Academy
Computing Science Dept
Computational Thinking Booklet V4
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SDD Unit
Questions
1.
Explain the purpose of the code.
2.
Choose from the following options the type of data that will be stored in the
variable band_name$ in line 5.
A.
Integer,
B. Real,
C. String
3. Choose from the following options the type of data that will be stored in the
variable ticket_cost in line 7.
A.
Integer,
B. Real,
C. String
4.
Describe the purpose of the FOR ... NEXT construct in lines 3 – 9.
5. Describe how the value of the numeric variable ‘total_cost’ is calculated in line 8.
Douglas Academy
Computing Science Dept
Computational Thinking Booklet V4
17
SDD Unit
2
Look at the code below
Line 1
LET correct$=“douglas”
Line 2
DO
Line 3
PRINT “Please enter your password”
Line 4
INPUT password$
Line 5
IF password$ <> correct$ THEN
Line 6
PRINT “Sorry wrong password.”
Line 7
END IF
Line 8
LOOP UNTIL password$ = correct$
Line 9
PRINT “Access granted”
Line 10
END
Douglas Academy
Computing Science Dept
Computational Thinking Booklet V4
18
SDD Unit
Questions
1. Explain what happens when you run the code.
2. Describe the purpose of the expression in Line 1.
3. Describe the purpose of the IF... THEN...END IF construct in lines 5 to 7.
4. Describe the purpose of the DO.. LOOP UNTIL in lines 2 to 8.
Douglas Academy
Computing Science Dept
Computational Thinking Booklet V4
19
SDD Unit