The lesson is suitable for GCSE / KS3 Computer Science (see other similar lessons in this series) To understand that more than one algorithm can be used to solve the same problem. To compare the efficiency of algorithms explaining how some algorithms are more efficient in solving algorithms than others, specifically space and time efficiency of algorithms Please leave a comment if you like the resource. Lesson plan Presentation on space efficiency that looks at a simple algorithm of adding up consecutive numbers (eg 1 + 2 + 3 + 4 … ) in a sequence, then compares this approach with using a loop and then looks at using an equation to solve the problem as an example of space efficiency in an algorithm. Pupils program these algorithms for themselves to see how lines of code can be reduced in a program. The above presentation is supported by three python programs (eg sequence, loop, equation python programs) Presentation on time efficiency that looks at two algorithms (one using a loop and another using an equation) to see which ones are more time efficient. Pupils program these algorithms to see how execution time of a program can be reduced. The above presentation is supported by two python programs (eg loop and equation python programs) The pupils are then given a program task to try to create a program that will calculate the nth term of the sequence 2, 4, 8, 16 in the most efficient way. A stretch and challenge exercise considers how to program a more difficult sequence of numbers Plenary presentation quiz to test pupils knowledge Homework looking at definitions of space and time efficiency and an example algorithm (answers provided)

The revision guide could form the basis of a revision guide at Key stage 3 and could be enhanced to include other topics. The revision guide covers the following IT topics: Hardware Software Input devices Storage media Output devices Modems Networking Spreadsheets Databases

The logic gates AND, OR, NOT, NAND, NOR, XOR A Level Computer Science (24 slides) The AND, OR, NOT, NAND, NOR, XOR logic gate presentation covers the following: - Understanding that logic gates can be represented by switches as ON / OFF states - Understanding the different states that can be represented by logic gates - Understanding that logic gates can be represented by truth tables and Boolean expressions

The word document presents five questions asking for a translation from ‘infix’ to ‘postfix’ and five questions from ‘postfix’ to ‘infix’ notation. There is a question asking to convert a postfix expression into a binary tree and then requiring a traversal of the binary tree using preorder, post order and inorder traversal. There is a question asking about the purpose of RPN and another question asking why humans use infix notation and computers sometimes use postfix notation (x6 questions sub divided into sections)

The presentation introduces the idea of properties and methods belonging to a class, being able to instantiate a class and produce an object and how many objects can be created from the class. The presentation describes the OOP characteristics behind inheritance, encapsulation and polymorphism. It gives six supporting examples using python code to demonstrate the above concepts. At the end of the presentation there is a challenge to create a program to illustrate the new ideas. This is supported by a class diagram that displays the relationship between the classes.

The presentation introduces the idea of data redundancy (repeating data) inside tables. It shows using clear diagrams how to avoid this by splitting a table into two separate tables and introducing a one to many relationship between these two tables. It goes onto show how to represent ‘many to many’ relationships using two ‘one to many’ relationships, before defining the two important keys; primary and foreign key. There is a word document worksheet where the pupils have to describe the relationships between entities.

Binary Crossword Starter (word doc) - There are four questions down and four questions across. - The students have to guess the word, then convert the first letter of the word to binary using ASCII code. - There is a copy of the ASCII code the students can refer to convert letters to binary. - There is an answer document included with the resource. The students end with a crossword completed in binary using the ASCII code.

A presentation that introduces the different data flow diagram symbols, one by one and explains how a data flow diagram can be constructed from a table. An example of a data flow diagram is given followed a challenge exercise.

The AND, OR, NOT logic gates (15 slides) GCSE & A Level Computer Science The AND, OR, NOT logic gate presentation covers the following: - Understanding that logic gates can be represented by switches as ON / OFF states - Understanding the different states that can be represented by logic gates - Understanding that logic gates can be represented by truth tables and Boolean expressions

Presentation on how a selection sort works. It includes: A presentation explaining the principle of operation behind a selection sort A presentation introducing the code written in python to perform a selection sort The selection sort python code in a separate text file.

The presentation introduces x7 validation rules; range check, type check, presence check, length check, lookup check, picture check and check digit check. Each one of the descriptions is supported with an example written in python and these have been uploaded as separate text files as part of the resource.

The presentation describes what a stack data structure is, introduces the principle operations of PUSH / POP along with the stack pointer using simple, easy to understand diagrams. The presentation includes pseudo code for the PUSH / POP operations and describes three uses of the stack data structure.

The presentation introduces Reverse Polish Notation (postfix notation) and compares it to infix / prefix notation. There are examples of these different notations and then a closer look at how to convert expressions between postfix to infix and vice versa. A more detailed example demonstrates how a stack is used to temporarily manipulate values to evaluate the expression. Finally uses of RPN are given at the end of the presentation.

Binary Addition Presentation (8 slides) GCSE & A Level Computer Science The Binary Addition presentation covers the following: - Comparing binary addition with denary addition - Understanding The rules of binary addition - Two practice questions

The presentation introduces five different data types; boolean, integer, real, date/time, string. Each slide describes the data type and gives examples of what they can represent.

A presentation that describes what recursion is, uses two pseudo code examples (eg sum numbers and factorial) to illustrate the programming technique, including the importance of using a base condition and the result if no condition is used. There are a series of programming challenges at the end of the presentation.

The presentation introduces the terms database, relationship, table, records, fields and data items to explain the structure of a database. It gives visual examples of these terms and relates them to a database hierarchy. It explains the different degrees of relationships and asks a question to label a table database structure. The resource also includes a follow on worksheet where the pupils drag and drop database definitions alongside each one of the database terms.

The presentation introduces the idea behind testing and covers the ideas behind the idea of creating a test plan, difference between a fault and an error and shows a blue screen error. It describes the importance of reliability, using different test data (typical, erroneous, exaggerated data) and how to formulate a test plan.

TCP/IP Protocol Stack presentation: x13 slides The resource is for pupils studying GCSE and A level Computer Science and explains the four layers of the TCP / IP protocol stack; the application, the transpor, the network and the data link layers. The presentation includes: - an overview and explanation of the different layers - the protocols and some of the tasks involved in each layer - using an example of sending some data through the different layers - a summary at the end of the transmission of this data and how it has changed on it's journey

The trace table questions begin with some simple examples written in pseudocode, using that output variables in a WHILE / FOR loop and begin to introduce two WHILE / FOR loops, before introducing a one dimensional list and then a two dimensional list as the last question. The resource comes with ten questions on the worksheet and answers. The resource is suitable for any examination board.