Totalling & Counting (Cambridge (CIE) O Level Computer Science)

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Written by: Robert Hampton

Reviewed by: James Woodhouse

Totalling & Counting

How do you use totalling in a program?

Totalling involves adding up values, often in a loop
A total variable is set to 0 at the beginning of the program and then updated within a loop, such as:

Pseudocode	Python
`Total ← 0` `FOR I ← 1 to 10` `INPUT Num` `TOTAL ← TOTAL + Num` `NEXT I` `OUTPUT Total`	`total = 0` `for i in range(1, 11):` `num = int(input("Enter a number: "))` `total = total + num` `print("Total:", total)`

Pseudocode

Python

Total ← 0

FOR I ← 1 to 10

INPUT Num

TOTAL ← TOTAL + Num

NEXT I

OUTPUT Total

total = 0

for i in range(1, 11):

num = int(input("Enter a number: "))

total = total + num

print("Total:", total)

How do you use counting in a program?

Counting involves keeping track of the number of times a particular event occurs
A count variable is set to 0 and then updated within a loop, such as:

Pseudocode	Python
`Count ← 0` `FOR I ← 1 to 10` `INPUT Num` `IF Num > 5` `THEN` `Count ← Count + 1` `ENDIF` `NEXT I` `OUTPUT Count`	`count = 0` `for i in range(1, 11):` `num = int(input("Enter a number: "))` `if num > 5:` `count = count + 1` `print("Count:", count)`

Pseudocode

Python

Count ← 0

FOR I ← 1 to 10

INPUT Num

IF Num > 5

THEN

Count ← Count + 1

ENDIF

NEXT I

OUTPUT Count

count = 0

for i in range(1, 11):

num = int(input("Enter a number: "))

if num > 5:

count = count + 1

print("Count:", count)

Worked Example

Write an algorithm using pseudocode that:

Inputs 20 numbers
Outputs how many of these numbers are greater than 50

[3]

Answer

FOR x ← 1 TO 20 [1]

INPUT Number

IF Number > 50

THEN

Total ← Total + 1 [1]

NEXT x

PRINT total [1]

Last updated: 18 April 2024

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