Choosing between INTEGER and REAL

Tip: Choose Save as PDF in the print dialog to download. Use A4 paper size.

Choosing between INTEGER and REAL

Name:
Date:
Class:
A

Quick Questions

Shade in the A or B circle for each question.

1. Which data type should you use to store the number of students in a class?
A INTEGER
B REAL
2. Which data type should you use to store the price of a sandwich, such as 3.75?
A REAL
B INTEGER
3. Which data type suits a variable called AverageMark that holds the mean of several test marks?
A INTEGER
B REAL
4. Which declaration is the better choice for the number of books in a bag? A: DECLARE Books : INTEGER B: DECLARE Books : REAL
A B: DECLARE Books : REAL
B A: DECLARE Books : INTEGER
5. True or false: a value that is whole today, such as a price of 5, should always be stored as INTEGER.
A False
B True
B

Match the Pairs

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

Left columnRight column
1DECLARE NumStudents : INTEGER ADECLARE NumSeats : INTEGER
2DECLARE AverageMark : REAL BDECLARE Price : REAL
3A price can include pence or cents, so it needs a data type that allows decimals CAn average mark can have a decimal part, so it should be declared as REAL. INTEGER cannot store 72.5.
4A value that is always a whole number, such as the number of seats in a room, uses INTEGER DStores a count of students, which is always a whole number
5DECLARE AverageMark : INTEGER AverageMark ← 72.5 EStores an average mark, which might have a decimal part
6DECLARE NumStudents : REAL FA count of students is always a whole number, so INTEGER is the better choice. REAL is not needed here.
C

Definitions

INTEGER or REAL
D

Fill in the Blanks

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

1.
DECLARE NumStudents : _______
2.
DECLARE Price : ____
3.
DECLARE AverageMark : ____ AverageMark ← 72.5
4.
DECLARE NumTickets : _______ NumTickets ← 4
5.
// Pocket money may include cents later DECLARE PocketMoney : ____
E

Spot the Error

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

Question 1
A DECLARE price : REAL
B DECLARE items : INTEGER
C price ← 4.50
D items ← 12.5
Question 2
A DECLARE avgMark : REAL
B DECLARE numStudents : REAL
C numStudents ← 30
D avgMark ← 67.5
Question 3
A DECLARE count : INTEGER
B count ← 12
C DECLARE price : INTEGER
D price ← 9.99
Question 4
A DECLARE total : INTEGER
B DECLARE average : INTEGER
C total ← 250
D average ← total / 4
Question 5
A DECLARE temp : INTEGER
B temp ← 21.5
C OUTPUT temp

Answer Key

Choosing between INTEGER and REAL
Section A: Quick Questions
Q1
A — INTEGER
Q2
A — REAL
Q3
B — REAL
Q4
B — A: DECLARE Books : INTEGER
Q5
A — False
Section B: Match the Pairs
Q1
DECLARE NumStudents : INTEGER → Stores a count of students, which is always a whole number
Q2
DECLARE AverageMark : REAL → Stores an average mark, which might have a decimal part
Q3
A price can include pence or cents, so it needs a data type that allows decimals → DECLARE Price : REAL
Q4
A value that is always a whole number, such as the number of seats in a room, uses INTEGER → DECLARE NumSeats : INTEGER
Q5
DECLARE AverageMark : INTEGER AverageMark ← 72.5 → An average mark can have a decimal part, so it should be declared as REAL. INTEGER cannot store 72.5.
Q6
DECLARE NumStudents : REAL → A count of students is always a whole number, so INTEGER is the better choice. REAL is not needed here.
Section C: Definitions
Q1
INTEGER or REAL — Use INTEGER for values that are always whole numbers, like a count of students. Use REAL if the value could have a decimal part, like a price or an average mark.
Section D: Fill in the Blanks
Q1
DECLARE NumStudents : INTEGER
Q2
DECLARE Price : REAL
Q3
DECLARE AverageMark : REAL AverageMark ← 72.5
Q4
DECLARE NumTickets : INTEGER NumTickets ← 4
Q5
// Pocket money may include cents later DECLARE PocketMoney : REAL
Section E: Spot the Error
Q1
D — items is an INTEGER, so it can only hold whole numbers. 12.5 has a decimal part. The line should be items ← 12.
Q2
B — A number of students is always a whole number, so it should be declared as INTEGER, not REAL.
Q3
C — A price such as 9.99 has a decimal part, so price must be declared as REAL. An INTEGER cannot store it.
Q4
B — An average can have a fractional part. 250 / 4 is 62.5, so average should be declared as REAL.
Q5
A — The temperature 21.5 has a decimal part, so temp must be REAL. INTEGER only holds whole numbers.