Presentation on theme: "Www.computerscienceuk.com The Scratch Calculator You are all going to be real computer programmers!!!"— Presentation transcript:
www.computerscienceuk.com The Scratch Calculator You are all going to be real computer programmers!!!
www.computerscienceuk.com This Half Term’s Project Computer Programming – The Scratch Calculator Demonstration
www.computerscienceuk.com Lesson Objectives Learning Objectives Understand how to create a sprite Understand how to create a new background Understand how to move the sprite Understand how to input values into scratch Understand where our inputs are stored Understand how to output values onto the screen Lesson Outcomes Create a simple program whereby the sprite (which can be moved by the user) asks the user a few questions and responds to the users answers. Literacy – Key Words SpriteAn object which can be programmed in scratch ScriptsA piece of programming code in scratch InputsValues which get sent from the user into the computer VariablesThe place where inputs get stored by the program OutputsThe values which get sent from the computer to the user
www.computerscienceuk.com Scratch Scratch is an application which allows you to ‘program’ It allows you to use and create ‘Sprites’ which are simply characters and objects It allows you to program these Sprites so that they move and interact with each other and the user.
www.computerscienceuk.com Familiarising yourself with ‘Scratch’ Instructions and Controls Scripts Area Sequence of Instructions Scripts Area Sequence of Instructions Sprites The Stage
www.computerscienceuk.com Designing a new sprite Demonstration
www.computerscienceuk.com Designing a new background Demonstration
www.computerscienceuk.com How do we program? Programs are not that different from us. In fact, programming is all about teaching the computer to think just like us (humans)…
www.computerscienceuk.com If a computer is a box… …think of a program as a man inside the box!
www.computerscienceuk.com …and programming is all about instructing the man to do what you want! “Tell me what to do and I will do it!!”
www.computerscienceuk.com The man in the computer (program) thinks just like a human. If we taught the man how to have a conversation with the computer user, what would be the first thing we would tell him to do?
www.computerscienceuk.com Inputs → Storage → Process → Output Conversations start with a question. In other words the man in the computer might ask the user for some information (INPUT). Example: “What is your name?” IN The user would then type IN their name! INPUT “What is your name?”
www.computerscienceuk.com Inputs → Storage → Process → Output Then the man in the computer will store the answer in its brain (STORAGE) and think about how to respond (PROCESS). 1.Remember the answer (STORE IT) 2.Think about how to respond (Process)
www.computerscienceuk.com Inputs → Storage → Process → Output The man in the computer would finally respond (OUTPUT). Example: “So, your name is BOB! What a great name!” The computer would display this on the screen (OUTPUT). OUTPUT
www.computerscienceuk.com Inputs → Storage → Process → Output All programs work in this way… Think of a word processor: INPUT STORAGE/PROCESS OUTPUT 1.Users can press a letter on a keyboard (input) 2.The computer stores this event and decide how to respond (storage/process) 3.And then display the letter on the screen (output)
www.computerscienceuk.com Inputs → Storage → Process → Output In Scratch, which of the following scripts will help us program the man (inside the computer) to demand an input from a user?
www.computerscienceuk.com The ASK script asks the user to enter (input) a value into scratch? Inputs → Storage → Process → Output
www.computerscienceuk.com What do you get when you ask a questions? ANSWER! answer Once you have inputted a value into scratch it is stored in a ‘variable’ called answer. This is what the script looks like Inputs → Storage → Process → Output
www.computerscienceuk.com What is a variable? In programming, a variable can be thought of as a storage box. The box may be given a name, and it may hold various different things. In scratch, is the name of the variable, and it will store what ever you type into scratch. Variable called ‘ANSWER’ Contents is anything we type in Storage
www.computerscienceuk.com Which of the following scripts do you think will help us program the man (inside the computer) to output a value onto the screen? Inputs → Storage → Process → Output
www.computerscienceuk.com Inputs Storage Outputs Which of the following scripts do you think will help us output a value onto the screen?
www.computerscienceuk.com The Join Script We can also join words and the ‘ANSWER’ together to create sentences:
www.computerscienceuk.com Summary INPUT SCRIPTS: STORAGE SCRIPTS: OUTPUT SCRIPTS: The “join” script is a nice extra to combine set text with the user’s text to form sentences when outputting to the screen
www.computerscienceuk.com Task 1 1.Open onto Scratch 2.Delete the cat and create a stick man sprite. 3.Program it to ask you your age 4.Then get the stickman to reply by saying something like, “Oh, years old is well old! I’m only 30mins old myself!” 5.Then try carry on programming some more questions and responses. 20 minutes
www.computerscienceuk.com Moving your Sprite In programming, things always happen in a set order – a sequence. Sequences are first written as a flow chart and then programmed in a game. If we want to move a sprite left the following sequence would have to occur: Press right arrow key Sprite faces to the right Sprite moves a step to the right In Scratch, we program the sprite like this:
www.computerscienceuk.com 2 nd Activity Create a new background, something quick and simple. Program your sprite so that it moves up, down, left and right when you press the arrow keys. 15 mins If you finish early, be the teacher and help others!!
www.computerscienceuk.com Plenary How do you create a sprite? How do you create a new background? How do you program movement in the sprite? Which script allows us to input values into scratch? Where are our inputs are stored? Which script allows us to output values onto the screen?
www.computerscienceuk.com Homework Complete the Lesson One Worksheet