Introduction to Scratch We will be using the Scratch Environment today, so please log in to the Scratch website (scratch.mit.edu)

Today we will… Review what we learned last class Discuss key concepts in programming – Sequence – Iteration – Conditional statements – Variables – User interface design

REVIEW OF LAST CLASS

Key concept: sequence To create a program you need to think systematically about the order of steps. Programs run from top to bottom and right to left. When programming, ask yourself: What needs to happen first in order for my program to work properly?

Key concept: sequence Think about it first: What is the order of events when this code runs? Try it out on Scratch!

Think, Pair, Share Think about it first: How did sequence play a role in the calculations you did last class? Discuss with a partner.

Key concept: iteration (looping) When a process or sequence of instructions (script) is repeated again and again, this is iteration The forever and repeat commands can be used for iteration When programming, ask yourself: Am I trying to run a series of instructions over and over?

Key concept: iteration (looping) What happens when this code runs? Can you picture it before trying? Try it out on Scratch!

Key concept: conditional statements Make programming very powerful Test a variable against a value and act a certain way depending on whether a condition is met The if and if-else commands check for a condition. When programming, ask yourself: Do I need to check that something has happened first before this section of code can run?

Key concept: conditional statements Think about it first: What are the two possible events in this code? Try it out on Scratch!

Key concept: variables Variables act as storage locations in a program. The variables category allows you to create a new variable and use it in your code. When programming, ask yourself: Do I need a way to store information?

Key concept: variables What is the variable here? How does it change? Try it out on Scratch!

Key concept: user interface design You can design your programs so that they require user interaction. Example: Clickable sprites to create buttons. When programming, ask yourself: Do I need the user to interact with my program?

Key concept: user interface design How is this program interactive? What does the user need to do? Try it out on Scratch!

Programming Challenge Log on to Moodle and go to programming 9 Find Key Concepts in Programming Read the instructions and complete for homework