5.7 & 5.8 Loops Practice & Make

Overview

Students practice the basics of loops including using while loops, for loops, and updating multiple screen elements with a for loop. Along the way students develop debugging practices with loops.

Using Programming Patterns and a step-by-step approach students make their own version of a Lock Screen Maker app. At the beginning of the lesson students are able to explore a working version of the app. They are then given the design elements of the app but begin with minimal starting code. A progression of levels guides students on the high level steps they should use to develop their app but leaves it to them to decide how to write the code. At the end students submit their apps which can be assessed using a provided rubric.

Purpose

This lesson is students primary opportunity to get hands on with loops in code prior to the Make activity in the following lesson. Give students as much class time as you can to work through these. For this lesson it's recommended that you place students in pairs as a support and to encourage discussion about the challenges or concepts they're seeing.

This lesson is students primary opportunity to get hands on with loops in code prior to the Make activity in the following lesson. Give students as much class time as you can to work through these. For this lesson it's recommended that you place students in pairs as a support and to encourage discussion about the challenges or concepts they're seeing.

Standards

CSP Conceptual Framework

AAP-2 - The way statements are sequenced and combined in a program determines the computed result. Programs incorporate iteration and selection constructs to represent repetition and make decisions to handle varied input values.

• • AAP-2.K - For iteration: a. Represent using iteration statements. b. Determine the result or side-effect of iteration statements.

  • AAP-2.K.2 - The exam reference sheet providesREPEAT n TIMES{ <block of statements>}in which the block of statements is executed n times.

  • AAP-2.K.3 - The exam reference sheet providesREPEAT UNTIL(condition){ <block of statements>}in which the code in block of statements is repeated until the Boolean expression condition evaluates to true.

  • AAP-2.K.4 - In REPEAT UNTIL(condition) iteration, an infinite loop occurs when the ending condition will never evaluate to true.

  • AAP-2.K.5 - In REPEAT UNTIL(condition) iteration, if the conditional evaluates to true initially, the loop body is not executed at all, due to the condition being checked before the loop.

  • AAP-2.L - Compare multiple algorithms to determine if they yield the same side effect or result.

  • AAP-2.L.1 - Algorithms can be written in different ways and still accomplish the same tasks.

  • AAP-2.L.2 - Algorithms that appear similar can yield different side effects or results.

  • AAP-2.L.5 - Different algorithms can be developed or used to solve the same problem.

CRD-2 - Developers create and innovate using an iterative design process that is user-focused, that incorporates implementation/feedback cycles, and that leaves ample room for experimentation and risk-taking.

• CRD-2.I - For errors in an algorithm or program: a. Identify the error. b. Correct the error.

• CRD-2.I.3 - A run-time error is a mistake in the program that occurs during the execution of a program. Programming languages define their own run-time errors.

• CRD-2.I.4 - An overflow error is an error that occurs when a computer attempts to handle a number that is outside of the defined range of values.

CSTA K-12 Computer Science Standards (2017)

AP - Algorithms & Programming

• 3A-AP-15 - Justify the selection of specific control structures when tradeoffs involve implementation, readability, and program performance and explain the benefits and drawbacks of choices made.

DA - Data & Analysis

• 3A-DA-12 - Create computational models that represent the relationships among different elements of data collected from a phenomenon or process.