Correcting Algorithms

Lesson Instructions

Watch and follow the YouTube video, the lesson contains three parts:

  1. Key Information and content - all you need to do here is watch and listen. We recommend you take some notes for this one!

  2. Learning activity - You are to complete an activity that requires you to correct a series of algorithms so that they do what is intended.

  3. Consolidation - these are past exam question and are for deliberate practice to check your understanding.

Task - Correcting Algorithms Activity

Task - Exam Questions - Deliberate Practice

Exam Questions - Web

Mark Scheme

Question 1 (a)

1 mark per bullet to max 2.

  • x = 20

  • y = 20

Question 1 (b)

One mark per bullet

  • Inputs are written the same as the algorithm given

  • New variable created to temporarily store value

  • Swaps are correctly made


x = input(“Enter first number:”)

y = input(“Enter second number:”)

temp = x

x = y

y = temp

Question 2

1 mark per bullet

  • Algorithm takes two inputs as per example

  • If used to check one value bigger than another and output correct variable

  • Elseif used to check the other option and output correct variable

  • Else used to confirm whether they are the same

NOTE: As long as the logic is there award marks.


num1 = input(“Enter number 1:”)

num2 = input(“Enter number 2:”)

if num1 > num2 then


elseif num2 > num1 then



print(“Numbers are the same”)