Book Image

Scratch 1.4: Beginner's Guide

Book Image

Scratch 1.4: Beginner's Guide

Overview of this book

If you have the imaginative power to design complex multimedia projects but can't adapt to programming languages, then Scratch 1.4: Beginner's Guide is the book for you. Imagine how good you'll feel when you drag-and-drop your way to interactive games, stories, graphic artwork, computer animations, and much more using Scratch even if you have never programmed before. This book provides teachers, parents, and new programmers with a guided tour of Scratch's features by creating projects that can be shared, remixed, and improved upon in your own lesson plans. Soon you will be creating games, stories, and animations by snapping blocks of "code" together. When you program you solve problems. In order to solve problems, you think, take action, and reflect upon your efforts. Scratch teaches you to program using a fun, accessible environment that's as easy as dragging and dropping blocks from one part of the screen to another. In this book you will program games, stories, and animations using hands-on examples that get you thinking and tinkering. For each project, you start with a series of steps to build something. Then you pause to put our actions into context so that you can relate our code to the actions on Scratch's stage. Throughout each chapter, you'll encounter challenges that encourage you to experiment and learn. One of the things you're really going to love is that, as you begin working through the examples in the book, you won't be able to stop your imagination and the ideas will stream as fast as you can think of them. Write them down. You'll quickly realize there are a lot of young minds in your home, classroom, or community group that could benefit from Scratch's friendly face. Teach them, please.
Table of Contents (17 chapters)
Scratch 1.4 Beginner's Guide
Credits
About the Author
About the Reviewer
Preface
Scratch Resources
Index

Double it or lump sum?


Let's refine our problem statement to include an interest calculation: Would you rather earn 4% interest on $15,000 for one month or receive $1 that doubles every day for 15 days?

To help us make the right choice, we will do both calculations. We'll show the results of the doubled amount using a graph, and we'll use a sprite to report the interest amount.

We'll build some user-input features into each calculation so that the user can experiment with variable amounts.

We'll begin by setting up the equation to calculate the doubled amount and its graph.

Double it

The doubling formula is relatively simple. Day two's value is twice as much as day one's. Day three's is twice as much as day two's, and on and on it goes.

We can represent the math with this equation:

newAmount = startAmount x 2

Before you begin, create a new sprite in the shape of a circle. The ellipsis tool in the Paint Editor works well for this. We'll use this sprite to draw the points on our graph, so make it...