Computer Science Principles Unit 5 Chapter 2 Lesson 16: Functions With Return Values

Learning Resource Type

Classroom Resource

Subject Area

Digital Literacy and Computer Science

Grade(s)

9, 10, 11, 12

Overview

In this lesson, students are introduced to the return command and learn to write their own functions that return values. Students first complete a simple unplugged activity based on the game Go Fish to introduce the concept of a return value. They will then complete a short sequence of exercises in Code Studio, which introduces preferred patterns for writing functions that return values. At the end of the sequence, students write and use functions that return values in a simple turtle driver app.

Students will be able to:
- use the return command to design functions.
- identify instances when a function with a return value can be used to contain frequently used computations within a program.
- design functions that return values to perform frequently needed computations within a program.

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Digital Literacy and Computer Science (2018) Grade(s): 09-12

DLCS18.HS.3
Differentiate between a generalized expression of an algorithm in pseudocode and its concrete implementation in a programming language.

Vocabulary

pseudocode
programming language

a.

approximated

b.

iteration
conditional statements
control structures

c.

iterative loop
selection constructs
recursion

Knowledge

Students know:

that differences exist in pseudocode and a programming language.
that programming languages have certain requirements for language and syntax.

a.

that some programs cannot return a result in a reasonable time frame, therefore approximations must be allowed in those cases.

b.

how to identify sequential statements, conditional statements, and/or iterations in code.
the differences between sequential statements, conditional statements, and/or iterations.
trade-offs exist with using one control structure over another.

c.

some decisions in a program will require the use of iterative loops, selection constructs, or recursion.

d.

programs can be written to satisfy a number of needs such as performance, reusability, and ease of implementation.
that most times, algorithms will differ based on the need of the program; performance, reusability, or ease of implementation.

e.

that programs can be written with specific priorities in mind.
that there are multiple correct ways to write a program.
that solutions are often chosen to meet the priority need of the program.

Skills

Students are able to:

distinguish between a generalized expression of an algorithm in pseudocode and its concrete implementation in a programming language.
point out similarities in vocabulary and syntax between pseudocode and an algorithm.
point out differences in vocabulary and syntax between pseudocode and an algorithm.

a.

explain that some algorithms do not lead to exact solutions in a reasonable amount of time and thus approximations are acceptable.

b.

identify sequential statements, conditional statements, and/or iterations in code.
identify tradeoffs associated with using one control structure over another.

c.

distinguish when a problem solution requires decisions to be made among alternatives or when a solution needs to be iteratively processed to arrive at a result.

d.

evaluate and select algorithms based on performance, reusability, and ease of implementation.

e.

explain how more than one algorithm may solve the same problem and yet be characterized with different priorities.

Understanding

Students understand that:

similarities and differences exist in pseudocode and programming code.
some programming languages more closely resemble pseudocode than do other programming languages.

a.

due to time or financial constraints, some programs may return an approximation of a solution.

b.

both benefits and drawbacks exist when selecting one control structure over another in a code.

c.

programs can use multiple methods to arrive at a solution.

d.

there are times when a program needs to be selected for a specific purpose, such as performance, reusability, and/or ease of implementation.

e.

multiple algorithms can solve the same problem.
algorithms can operate with a specific priority in mind, such as speed, simplicity, and/or safety.

Digital Literacy and Computer Science (2018) Grade(s): 09-12

DLCS18.HS.6
Decompose problems into smaller components through systematic analysis, using constructs such as procedures, modules, and/or objects, with parameters, and which return a result.

Vocabulary

parameters
procedures
modules
objects
control structures

Knowledge

Students know:

removing unessential details can make a process simpler.
control structures can assist in programming decisions.
how to create a program that returns a result.

Skills

Students are able to:

decompose a problem.
create a program that returns a result.
implement control structures.

Understanding

Students understand that:

removing unessential details can make a process simpler.
control structures can assist in programming decisions.

Digital Literacy and Computer Science (2018) Grade(s): 09-12

DLCS18.HS.8
Demonstrate code reuse by creating programming solutions using libraries and Application Programming Interfaces.

Vocabulary

code
programming languages
Application Programming Interfaces

Knowledge

Students know:

how to design a programming application that reuses code from programming libraries and code created in previous applications.

Skills

Students are able to:

reuse code from previous applications, code libraries, or APIs to reduce coding workload.

Understanding

Students understand that:

reuse of code can be time
saving.
code may be written and shared in code libraries or may be accessible as an API.

CR Resource Type

Lesson/Unit Plan

Resource Provider

Code.org

License Type

Custom

https://curriculum.code.org/csp-18/unit5/16/

Custom License Type (URL)

https://code.org/tos

Approved Date

2019-04-23

Design by Adaptive Theme