Chapter 1: Building Blocks of Programming

Transcription

1 Chapter 1: Building Blocks of Programming (Completion Time: 4 weeks) Topics: Pseudocode An introductions into express computational ideas in a language that can be translated to code. Used correctly, thinking in pseudocode may also help find bugs in your program before you even begin writing a single line of code! Scratch Create your first program using a drag and drop block based language called Scratch, which will allow students to learn concepts without getting mired in syntax. Syntax Moving away from a block-based language and more toward C, students will explore the details of how to express programming concepts in a text based language. Variables Develop an understanding of a variable as a container in which you can store things. Students will then be able to use and update their variables throughout the program. Data types Every time students declare a variable they must bringing it into existence and specify its type. Students will explore the different variable types in C as well as the differences between static and dynamic typing. Operators

2 Showing how we program arithmetic and assignment operations while noting the idiosyncrasies of left gets right where the expression x = 10 means x gets the value of 10. Boolean Expressions and Conditionals Conditional branching using Boolean expressions are how we as programmers make decisions in our programs. They empower us to take different forks in the road, allowing for different behaviors or different user experiences. Loops Instead of copying and pasting the same line(s) of code back-to-back, which can get clunky. All modern programming languages contain some variations on the construction of a loop, which permits iteration and repetition. Central Focus: Students begin to apply computational thinking, learning to express ideas first in pseudocode, then a visual language, Scratch, and finally, a text based language, C. They are introduced to various programming elements, and begin writing basic programs with proper syntax. Assignments: Programming Problem: Scratch To be completed with Scratch EU 1.1 Creative development can be an essential process for creating EU 1.2 Computing enables people to use creative development processes to EU 1.3 Computing can extend traditional forms of human expression and experience. EU 2.2 Multiple levels of abstraction are used to write programs or create other

3 EU 5.4 Programs are developed, maintained, and used by people for different LO Apply a creative development process when creating computational artifacts. LO Create a computational artifact for creative expression. LO Create a computational artifact using computing tools and techniques to solve a problem. LO Use computing tools and techniques for creative expression. The mission is, quite simply, to have fun with Scratch and implement a project of student s choice (be it an animation, a game, interactive art, or anything else). Programming Problem: Binary Bulbs To be completed with Scratch EU 1.2 Computing enables people to use creative development processes to EU 5.4 Programs are developed, maintained, and used by people for different LO Create a computational artifact using computing tools and techniques to solve a problem. LO Create a new computational artifact by combining or modifying existing artifacts. Students will modify an existing Scratch program to add functionality and additional features.

4 Programming Problem: Hello To be completed with Syntax EU 1.2 Computing enables people to use creative development processes to EU 1.3 Computing can extend traditional forms of human expression and experience. LO Create a computational artifact for creative expression. LO Use computing tools and techniques for creative expression. Students will setup their own instance of the CS50 IDE. Upon completion they will create, compile, and execute their first C program. Programming Problem: Fahrenheit To be completed with Operators EU 5.5 Programming uses mathematical and logical concepts. LO Employ appropriate mathematical and logical concepts in programming. Using C, students will build a program, which can convert from degrees Celsius to degrees Fahrenheit. Programming Problem: Pennies

5 To be completed with Operators EU 2.1 A variety of abstractions built on binary sequences can be used to represent all digital data. EU 2.2 Multiple levels of abstraction are used to write programs or create other EU 5.2 People write programs to execute algorithms. LO Describe the variety of abstractions used to represent data. LO Explain how programs implement algorithms. Write a program that calculates exponential growth based on an initial amount of pennies. Programming Problem: Skittles To be completed with Boolean Expressions and Conditionals EU 1.1 Creative development can be an essential process for creating EU 1.2 Computing enables people to use creative development processes to EU 1.3 Computing can extend traditional forms of human expression and experience. EU 2.1 A variety of abstractions built on binary sequences can be used to represent all digital data. EU 2.2 Multiple levels of abstraction are used to write programs or create other EU 4.1 Algorithms are precise sequences of instructions for processes that can be executed by a computer and are implemented using programming languages. EU 5.4 Programs are developed, maintained, and used by people for different EU 5.5 Programming uses mathematical and logical concepts.

6 LO Apply a creative development process when creating computational artifacts. LO Create a computational artifact for creative expression. LO Create a computational artifact using computing tools and techniques to solve a problem. LO Create a new computational artifact by combining or modifying existing artifacts. LO Use computing tools and techniques for creative expression. LO Explain how binary sequences are used to represent digital data. LO Develop an algorithm for implementation in a program. LO Express an algorithm in a language. LO Employ appropriate mathematical and logical concepts in programming. Students will begin using C functions to implement a pseudorandom guessing game. Programming Problem: Greedy To be completed with Boolean Expressions and Conditionals EU 1.1 Creative development can be an essential process for creating EU 2.2 Multiple levels of abstraction are used to write programs or create other EU 3.3 There are trade-offs when representing information as digital data. EU 4.1 Algorithms are precise sequences of instructions for processes that can be executed by a computer and are implemented using programming languages. EU 5.2 People write programs to execute algorithms.

7 EU 5.4 Programs are developed, maintained, and used by people for different EU 5.5 Programming uses mathematical and logical concepts. EU 7.4 Computing innovations influence and are influenced by the economic, social, and cultural contexts in which they are designed and used. LO Apply a creative development process when creating computational artifacts. LO Analyze how data representation, storage, security, and transmission of data involve computational manipulation of information. LO Develop an algorithm for implementation in a program. LO Express an algorithm in a language. LO Explain how programs implement algorithms. LO Employ appropriate mathematical and logical concepts in programming. LO Explain the connections between computing and real-world contexts, including economic, social, and cultural contexts. Students will implement algorithms to create a program that will print the least number of coins needed to give a specific amount of money. Programming Problem: ISBN To be completed with Loops EU 1.1 Creative development can be an essential process for creating EU 1.2 Computing enables people to use creative development processes to EU 1.3 Computing can extend traditional forms of human expression and experience. EU 2.1 A variety of abstractions built on binary sequences can be used to represent all digital data.

8 EU 2.2 Multiple levels of abstraction are used to write programs or create other EU 4.1 Algorithms are precise sequences of instructions for processes that can be executed by a computer and are implemented using programming languages. EU 5.4 Programs are developed, maintained, and used by people for different EU 5.5 Programming uses mathematical and logical concepts. LO Apply a creative development process when creating computational artifacts. LO Create a computational artifact for creative expression. LO Create a computational artifact using computing tools and techniques to solve a problem. LO Create a new computational artifact by combining or modifying existing artifacts. LO Use computing tools and techniques for creative expression. LO Describe the variety of abstractions used to represent data. LO Develop an algorithm for implementation in a program. LO Express an algorithm in a language. LO Employ appropriate mathematical and logical concepts in programming. The goal is to write a program to validate ISBN numbers by implementing a provided algorithm. Programming Problem: Mario To be completed with Loops

9 EU 1.2 Computing enables people to use creative development processes to EU 2.1 A variety of abstractions built on binary sequences can be used to represent all digital data. EU 2.2 Multiple levels of abstraction are used to write programs or create other EU 4.1 Algorithms are precise sequences of instructions for processes that can be executed by a computer and are implemented using programming languages. EU 5.4 Programs are developed, maintained, and used by people for different EU 5.5 Programming uses mathematical and logical concepts. LO Create a computational artifact using computing tools and techniques to solve a problem. LO Describe the variety of abstractions used to represent data. LO Develop an algorithm for implementation in a program. LO Express an algorithm in a language. LO Employ appropriate mathematical and logical concepts in programming. Write a program, using loops, to print out the exact number of spaces and hashes to form a half pyramid in the terminal. Programming Problem: Credit (HACKER) To be completed with Loops EU 1.1 Creative development can be an essential process for creating

10 EU 1.2 Computing enables people to use creative development processes to EU 1.3 Computing can extend traditional forms of human expression and experience. EU 2.1 A variety of abstractions built on binary sequences can be used to represent all digital data. EU 2.2 Multiple levels of abstraction are used to write programs or create other EU 4.1 Algorithms are precise sequences of instructions for processes that can be executed by a computer and are implemented using programming languages. EU 5.4 Programs are developed, maintained, and used by people for different EU 5.5 Programming uses mathematical and logical concepts. LO Apply a creative development process when creating computational artifacts. LO Create a computational artifact for creative expression. LO Create a computational artifact using computing tools and techniques to solve a problem. LO Create a new computational artifact by combining or modifying existing artifacts. LO Use computing tools and techniques for creative expression. LO Describe the variety of abstractions used to represent data. LO Develop an algorithm for implementation in a program. LO Express an algorithm in a language. LO Employ appropriate mathematical and logical concepts in programming. Students will write a program, which takes in a credit card number and returns the company it s from, or that it s an invalid number.

11 Essential Questions: How are algorithms implemented and executed on computers and computational devices? Why are some languages better than others when used to implement algorithms? How can use of variables, loops, and conditionals improve the design of a program? How do variables, loops, and conditionals allow for more complexity in programs? How do computer programs implement algorithms? How do people develop and test computer programs? Which mathematical and logical concepts are fundamental to computer programming? How are vastly different kinds of data, physical phenomena, and mathematical concepts represented on a computer? Ways to Launch the Lesson: Pseudocode Have students choose an algorithmic math procedure they know how to do (For example, solving the quadratic equation), and have them express the procedure in words. If there s time, students can swap procedures and try to guess what the written procedure is supposed to do. Scratch Because this topic is very specific, a teacher could introduce Scratch by having students play some games created in Scratch, either individually or as a class. The game used in lecture is: Syntax Prepare syntactically incorrect English sentences (missing punctuation, etc). Have students try to decode their meaning. Are there sentences that could mean more than one thing? Explain why computers cannot compile programs with incorrect syntax.

12 Variables Run a demonstration where selected students try to sum up a number via one sheet of paper without talking. Invite around 4 students to the front, and draw a box on the whiteboard. The first student writes a value there. The other students write a number value on a sheet of paper. Have each student add their number to the number on the board, thus updating the variable. Data Types Have students think of a list of how many types of data they think a computer can store. Likely, you ll end up with responses like pictures, videos which is an opportunity to revisit how bits and bytes store data. Operators Have students think about operations from math. Have them review the order of operations. Use examples of expressions with similar numbers and operations but different parentheses to show the importance of placement both in math and computer science alike. Boolean Expressions and Conditionals Have students articulate how they have their scratch programs make decisions. When have we decided the cat should meow? (Using a Boolean). Loops Have students list the most repetitive tasks they have to do in everyday life (for instance, folding each t-shirt, washing each dish, etc). Discuss when would loops be useful in a real-world context. Demos and Activities: Everyday Algorithms in Real Life Have students use their written assignment 0-2. Students should volunteer to demonstrate another student s algorithm, to illustrate how quickly things can go off track Materials:

13 If a student turns in a particularly compelling algorithm (an interesting task), it may be worth bringing in materials so that the instructions can be carried out. While Loops in Real Life Have a student instruct another student to walk from one location to another location in the room. The challenge: You can only instruct one step at a time. Then, introduce loops and conditions, so that the statement walk forward until you reach a wall is valid. Error Checking As David does in lecture, start with a simple but syntactically correct program. Then, add functionality to it but make syntax errors along the way, soliciting input from the class to fix them.