A constant's value must be a literal
Name:
Date:
Class:
A
Quick Questions
Shade in the A or B circle for each question.
1. Which constant declaration is valid in Cambridge pseudocode?
2. Which constant declaration is NOT valid?
3. True or false: CONSTANT Pi ← 3.14 is a valid constant declaration.
4. Why is CONSTANT Total ← Rate * 2 invalid?
5. Which one gives a constant a literal value?
B
Match the Pairs
Draw a line connecting each item on the left to its match on the right.
| Left column | Right column | |
|---|---|---|
| 1CONSTANT Rate ← 6.50 | ACONSTANT MaxScore ← 100 | |
| 2CONSTANT Total ← Rate * 2 | BThe constant is set to another constant (Rate), not a literal. Use a literal such as CONSTANT Copy ← 6.50. | |
| 3A constant's value must be a literal, so a number written directly is allowed | CThe value is an expression using a variable. Use a literal such as CONSTANT Tax ← 0.2. | |
| 4A constant's value must be a literal, so a text value written directly in quotes is allowed | DNot valid: the value is an expression, not a literal | |
| 5CONSTANT Copy ← Rate | EValid: the constant is set to the literal value 6.50 | |
| 6CONSTANT Tax ← Price * 0.2 | FCONSTANT School ← "Oakfield" |
C
Definitions
CONSTANT Rate ← 6.50
D
Fill in the Blanks
Complete each line of code by filling in the missing parts.
1.
________ Rate ← 6.50
2.
CONSTANT Rate _ 6.50
3.
// The maximum score is 100
CONSTANT MaxScore ← ___
4.
CONSTANT Rate ← 5
// Literal for double the rate
CONSTANT Double ← __
5.
DECLARE Count : INTEGER
________ Limit ← 10
E
Spot the Error
Shade in the letter of the line that contains an error.
Question 1
A
DECLARE Price : REAL
B
CONSTANT VatRate ← Price * 0.2
C
Price ← 10.00
D
OUTPUT Price * VatRate
Question 2
A
CONSTANT Rate ← 6.50
B
CONSTANT Double ← Rate * 2
C
OUTPUT Rate, Double
Question 3
A
CONSTANT Rate ← 6.50
B
DECLARE Hours : INTEGER
C
Hours ← 4
D
CONSTANT Copy ← Rate
Question 4
A
DECLARE Name : STRING
B
CONSTANT School ← Name
C
Name ← "Sam"
D
OUTPUT Name, School
Question 5
A
CONSTANT Width ← 4
B
CONSTANT Height ← 5
C
CONSTANT Area ← Width * Height
D
OUTPUT Area
Answer Key
A constant's value must be a literal
Section A: Quick Questions
Q1
A — CONSTANT Rate ← 6.50
Q2
A — CONSTANT Copy ← Rate
Q3
A — True, 3.14 is a literal value
Q4
B — The value is an expression, not a literal
Q5
B — CONSTANT Greeting ← "Hello"
Section B: Match the Pairs
Q1
CONSTANT Rate ← 6.50 → Valid: the constant is set to the literal value 6.50
Q2
CONSTANT Total ← Rate * 2 → Not valid: the value is an expression, not a literal
Q3
A constant's value must be a literal, so a number written directly is allowed → CONSTANT MaxScore ← 100
Q4
A constant's value must be a literal, so a text value written directly in quotes is allowed → CONSTANT School ← "Oakfield"
Q5
CONSTANT Copy ← Rate → The constant is set to another constant (Rate), not a literal. Use a literal such as CONSTANT Copy ← 6.50.
Q6
CONSTANT Tax ← Price * 0.2 → The value is an expression using a variable. Use a literal such as CONSTANT Tax ← 0.2.
Section C: Definitions
Q1
CONSTANT Rate ← 6.50 — A constant must be set to a literal value, such as 6.50. It cannot be given a variable, another constant or an expression like Rate * 2.Section D: Fill in the Blanks
Q1
CONSTANT Rate ← 6.50Q2
CONSTANT Rate ← 6.50Q3
// The maximum score is 100
CONSTANT MaxScore ← 100Q4
CONSTANT Rate ← 5
// Literal for double the rate
CONSTANT Double ← 10Q5
DECLARE Count : INTEGER
CONSTANT Limit ← 10Section E: Spot the Error
Q1
B — A constant's value must be a literal. Price * 0.2 uses a variable in an expression. It should be CONSTANT VatRate ← 0.2.
Q2
B — Rate * 2 is an expression, so it cannot be a constant's value. Use a literal: CONSTANT Double ← 13.00.
Q3
D — A constant cannot be set to another constant. Rate is a name, not a literal. It should be CONSTANT Copy ← 6.50.
Q4
B — A constant cannot be given a variable. Name is a variable, not a literal. It should be CONSTANT School ← "Oakwood".
Q5
C — Width * Height is an expression made from two constants. A constant needs a literal value: CONSTANT Area ← 20.