Classroom Resource

Divide and Conquer

Subject Area

Digital Literacy and Computer Science

Grade(s)

5, 6, 7, 8

Overview

Santa’s Dirty Socks

This activity introduces the idea of “divide and conquer” using a fictitious but serious problem – a pair of dirty socks have accidentally been wrapped in one of the presents that Santa is about to deliver, and he needs to figure out which one to avoid a child getting a nasty surprise.

You can either play the video (linked in the activity) or download the PDF of the book (see the PDF files in the link to the activity) to read aloud or give to students.

The solution in the story points out that when there are 1024 boxes to test, instead of having to open all of them until the socks are found, one half can be eliminated at a time, and repeatedly halving the problem very quickly narrows it down to one box (the size of the problem starts at 1024, then with one weighing there are 512 boxes, then 256, 128, 64, 32, 16, 8, 4, 2 and 1.) This idea comes up frequently in the design of fast computer algorithms.

Digital Literacy and Computer Science (2018) Grade(s): 5

DLCS18.5.2

Create an algorithm to solve a problem while detecting and debugging logical errors within the algorithm.

Unpacked Content

UP:DLCS18.5.2

Vocabulary

  • algorithm
  • debug
  • detect
  • logical errors

Knowledge

Students know:
  • an algorithm is a logical set of steps to solve a problem.
  • detecting and debugging logical errors within an algorithm will ensure the algorithm serves to solve a problem successfully.

Skills

Students are able to:
  • create an algorithm to solve a problem while detecting and debugging logical errors within the algorithm.

Understanding

Students understand that:
  • debugging an algorithm is searching for logical errors within the algorithm.
  • an algorithm is a set of steps to solve a problem.
  • how to create an algorithm to solve a problem while detecting and debugging logical errors within the algorithm.
Digital Literacy and Computer Science (2018) Grade(s): 5

DLCS18.5.3

Create an algorithm that is defined by simple pseudocode.

Unpacked Content

UP:DLCS18.5.3

Vocabulary

  • algorithm
  • pseudocode

Knowledge

Students know:
  • simple pseudocode resembles language used to communicate with computers.

Skills

Students are able to:
  • create an algorithm that is written in simple pseudocode.

Understanding

Students understand that:
  • an algorithm that is written in simple pseudocode is similar to an algorithm written using a programming language.
Digital Literacy and Computer Science (2018) Grade(s): 6

DLCS18.6.5

Identify algorithms that make use of sequencing, selection or iteration.

Unpacked Content

UP:DLCS18.6.5

Vocabulary

algorithm sequence selection iteration

Knowledge

Students know:
  • differences between the three basic programming structures.

Skills

Students are able to:
  • explain the differences in sequencing, selection, and iteration.

Understanding

Students understand that:
  • differences exist in sequencing, selection, and iteration.
Digital Literacy and Computer Science (2018) Grade(s): 7

DLCS18.7.3

Create algorithms that demonstrate sequencing, selection or iteration.

Unpacked Content

UP:DLCS18.7.3

Vocabulary

  • algorithm
  • sequence
  • selection
  • iteration

Knowledge

Students know:
  • how to use the programming structures to create algorithms and how many algorithms make use of all three programming structures.

Skills

Students are able to:
  • create and recognize various programming structures found in algorithms.

Understanding

Students understand that:
  • each structure sequencing, selections, and iterations have a purpose.
Digital Literacy and Computer Science (2018) Grade(s): 7

DLCS18.7.6

Create and organize algorithms in order to automate a process efficiently.

Unpacked Content

UP:DLCS18.7.6

Vocabulary

  • algorithm

Knowledge

Students know:
  • algorithms can be used to automate a process efficiently.

Skills

Students are able to:
  • use search and sort algorithms to automate organizing a set.

Understanding

Students understand that:
  • algorithms organized and applied to the appropriate task can significant increase proficiency.
Digital Literacy and Computer Science (2018) Grade(s): 8

DLCS18.8.5

Discuss the efficiency of an algorithm or technology used to solve complex problems.

Unpacked Content

UP:DLCS18.8.5

Knowledge

Students know:
  • that many solutions exist to solve a problem.

Skills

Students are able to:
  • communicate their opinion on the efficiency of problem solving methods.

Understanding

Students understand that:
  • while many solutions exist for a problem, some are better suited to meet specific needs, such as efficiency.
Digital Literacy and Computer Science (2018) Grade(s): 8

DLCS18.8.6

Describe how algorithmic processes and automation increase efficiency.

Unpacked Content

UP:DLCS18.8.6

Vocabulary

  • algorithmic process
  • automation

Knowledge

Students know:
  • how algorithmic processes and automation have increased efficiency.

Skills

Students are able to:
  • explain how algorithmic processes and automation increase efficiency.

Understanding

Students understand that:
  • automation is a useful tool for increasing efficiency.
  • while many things can and have been automated, not everything can be automated using algorithmic processes.
Link to Resource
https://classic.csunplugged.org/divideandconquer/

CR Resource Type

Learning Activity

Resource Provider

CS Unplugged
Accessibility

Accessibility

Text Resources: Content is organized under headings and subheadings
Video resources: includes closed captioning or subtitles
License

License Type

Attribution Non-Commercial Share Alike

Comments or Notes

This is a free resource from CS Unplugged.

Approved Date

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