Learning Resource Type

Classroom Resource

Computer Science Principles Unit 3 Chapter 1 Lesson 9: Looping and Random Numbers

Subject Area

Digital Literacy and Computer Science

Grade(s)

9, 10, 11, 12

Overview

Students learn to use random values and looping to create variation in their drawings and quickly duplicate objects they wish to appear in their digital scenes many times. Students will be presented with a version of the for loop which only enables them to change the number of times the loop runs. This block is essentially a "repeat" block and will be presented that way. Students will also be presented with blocks which enable them to choose a random number within a given range. Together these blocks enable students to create more complex backgrounds for digital scenes by randomly placing simple objects within the background of their scene. Students use these tools to step through the Under the Sea exemplar digital scene.

Students will be able to:
- use a loop in a program to simplify the expression of repeated tasks.
- identify appropriate situations in a program for using a loop.
- use random values within a loop to repeat code that behaves differently each time it is executed.

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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.

    Unpacked Content

    UP:DLCS18.HS.3

    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.
    Link to Resource

    CR Resource Type

    Lesson/Unit Plan

    Resource Provider

    Code.org
    Accessibility
    License

    License Type

    Custom
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