Lesson Summary


Students continue learning about iteration by using while loops and nested iteration. Students work through a guided tutorial on while loops and learn more turtle graphics features.  They also have the opportunity to practice collaboratively writing programs using for loops, while loops, and turtle graphics.  Throughout the lesson, students are given the opportunity to use their journal as a reflective tool.


  • Students will know that iteration can be performed in Python using while loops.  
  • Students will understand that for and while loops can be written (nested) inside of other for and while loops.
  • Students will share the workload by providing contributions to an overall collaborative effort.


  1. Getting Started (5 min)
  2. Guided Activity (15 min) - for and while loops with turtle graphics
  3. Collaborative Activity (25 min) - Shared coding of an iterative program
  4. Wrap Up (5 min) - Journal Activity

Learning Objectives

CSP Objectives

Big Idea - Creativity
  • EU 1.1 - Creative development can be an essential process for creating computational artifacts.
    • LO 1.1.1 - Apply a creative development process when creating computational artifacts. [P2]
      • EK 1.1.1B - Creating computational artifacts employs an iterative and often exploratory process to translate ideas into tangible form.
  • EU 1.2 - Computing enables people to use creative development processes to create computational artifacts for creative expression or to solve a problem.
    • LO 1.2.1 - Create a computational artifact for creative expression. [P2]
      • EK 1.2.1E - Creative expressions in a computational artifact can reflect personal expressions of ideas or interests.
    • LO 1.2.2 - Create a computational artifact using computing tools and techniques to solve a problem. [P2]
      • EK 1.2.2A - Computing tools and techniques can enhance the process of finding a solution to a problem.
    • LO 1.2.3 - Create a new computational artifact by combining or modifying existing artifacts. [P2]
      • EK 1.2.3A - Creating computational artifacts can be done by combining and modifying existing artifacts or by creating new artifacts.
    • LO 1.2.4 - Collaborate in the creation of computational artifacts. [P6]
      • EK 1.2.4A - A collaboratively created computational artifact reflects effort by more than one person.
      • EK 1.2.4D - Effective collaboration strategies enhance performance.
      • EK 1.2.4E - Collaboration facilitates the application of multiple perspectives (including sociocultural perspectives) and diverse talents and skills in developing computational artifacts.
      • EK 1.2.4F - A collaboratively created computational artifact can reflect personal expressions of ideas.
Big Idea - Algorithms
  • EU 4.1 - Algorithms are precise sequences of instructions for processes that can be executed by a computer and are implemented using programming languages.
    • LO 4.1.1 - Develop an algorithm for implementation in a program. [P2]
      • EK 4.1.1A - Sequencing, selection, and iteration are building blocks of algorithms.
      • EK 4.1.1B - Sequencing is the application of each step of an algorithm in the order in which the statements are given.
      • EK 4.1.1C - Selection uses a Boolean condition to determine which of two parts of an algorithm is used.
      • EK 4.1.1D - Iteration is the repetition of part of an algorithm until a condition is met or for a specified number of times.
      • EK 4.1.1F - Using existing correct algorithms as building blocks for constructing a new algorithm helps ensure the new algorithm is correct.
      • EK 4.1.1G - Knowledge of standard algorithms can help in constructing new algorithms.
      • EK 4.1.1H - Different algorithms can be developed to solve the same problem.
      • EK 4.1.1I - Developing a new algorithm to solve a problem can yield insight into the problem.
    • LO 4.1.2 - Express an algorithm in a language. [P5]
      • EK 4.1.2A - Languages for algorithms include natural language, pseudocode, and visual and textual programming languages.
      • EK 4.1.2C - Algorithms described in programming languages can be executed on a computer.
      • EK 4.1.2G - Every algorithm can be constructed using only sequencing, selection, and iteration.
Big Idea - Programming
  • EU 5.1 - Programs can be developed for creative expression, to satisfy personal curiosity, to create new knowledge, or to solve problems (to help people, organizations, or society).
    • LO 5.1.1 - Develop a program for creative expression, to satisfy personal curiosity, or to create new knowledge. [P2]
      • EK 5.1.1A - Programs are developed and used in a variety of ways by a wide range of people depending on the goals of the programmer.
      • EK 5.1.1B - Programs developed for creative expression, to satisfy personal curiosity, or to create new knowledge may have visual, audible, or tactile inputs and outputs.
      • EK 5.1.1C - Programs developed for creative expression, to satisfy personal curiosity, or to create new knowledge may be developed with different standards or methods than programs developed for widespread distribution.
      • EK 5.1.1D - Additional desired outcomes may be realized independently of the original purpose of the program.
    • LO 5.1.2 - Develop a correct program to solve problems. [P2]
    • LO 5.1.3 - Collaborate to develop a program. [P6]
  • EU 5.2 - People write programs to execute algorithms.
    • LO 5.2.1 - Explain how programs implement algorithms. [P3]
      • EK 5.2.1A - Algorithms are implemented using program instructions that are processed during program execution.
      • EK 5.2.1B - Program instructions are executed sequentially.
      • EK 5.2.1C - Program instructions may involve variables that are initialized and updated, read, and written.
      • EK 5.2.1D - An understanding of instruction processing and program execution is useful for programming.
      • EK 5.2.1E - Program execution automates processes.
  • EU 5.4 - Programs are developed, maintained, and used by people for different purposes.
    • LO 5.4.1 - Evaluate the correctness of a program. [P4]
      • EK 5.4.1E - Locating and correcting errors in a program is called debugging the program.
      • EK 5.4.1F - Knowledge of what a program is supposed to do is required in order to find most program errors.
      • EK 5.4.1G - Examples of intended behavior on specific inputs help people understand what a program is supposed to do.
      • EK 5.4.1H - Visual displays (or different modalities) of program state can help in finding errors.
      • EK 5.4.1I - Programmers justify and explain a program’s correctness.
  • EU 5.5 - Programming uses mathematical and logical concepts.
    • LO 5.5.1 - Employ appropriate mathematical and logical concepts in programming. [P1]
      • EK 5.5.1A - Numbers and numerical concepts are fundamental to programming.
      • EK 5.5.1E - Logical concepts and Boolean algebra are fundamental to programming.
      • EK 5.5.1F - Compound expressions using and, or, and not are part of most programming languages.
      • EK 5.5.1G - Intuitive and formal reasoning about program components using Boolean concepts helps in developing correct programs.

Math Common Core Practice:

  • MP1: Make sense of problems and persevere in solving them.
  • MP2: Reason abstractly and quantitatively.
  • MP5: Use appropriate tools strategically.
  • MP6: Attend to precision.
  • MP7: Look for and make use of structure.
  • MP8: Look for and express regularity in repeated reasoning.

Common Core ELA:

  • RST 12.3 - Precisely follow a complex multistep procedure
  • RST 12.4 - Determine the meaning of symbols, key terms, and other domain-specific words and phrases
  • RST 12.9 - Synthesize information from a range of sources
  • WHST 12.2 - Write informative/explanatory texts, including the narration of historical events, scientific procedures/experiments, or technical processes

NGSS Practices:

  • 3. Planning and carrying out investigations
  • 5. Using mathematics and computational thinking
  • 6. Constructing explanations (for science) and designing solutions (engineering)
  • 8. Obtaining, evaluation, and communicating information

Key Concepts

  • Students will describe how iteration can be performed in Python using while loops.  
  • Students will demonstrate that for and while loops can be written (nested) inside of other for and while loops.
  • Students will describe programs that are developed for creative expression, to satisfy personal curiosity, or to create new knowledge and that these programs may be developed with different standards or methods than programs developed for widespread distribution.
  • Students will work together to facilitate collaborative work.

Essential Questions

  • How can computing and the use of computational tools foster creative expression?
  • How are programs developed to help people, organizations or society solve problems?
  • How are programs used for creative expression, to satisfy personal curiosity or to create new knowledge?
  • How do people develop and test computer programs?
  • Which mathematical and logical concepts are fundamental to computer programming?

Teacher Resources

Student computer usage for this lesson is: required

In the Lesson Resources folder:

  • Guided activity: "Turtle Graphics Guided Activity: The while loop" in the Lesson Resources folder


Lesson Plan

Getting Started (5 min)

What will be displayed at the end of this program?

for x in range (0, 8):
   y += 1 print (y)

Introduction of Content (15 min)

  • Use the guided activity ("Turtle Graphics Guided Activity: The while loop" in the lesson folder) to discuss while loops and nested iteration.
  • To save time, have these programs open in your IDE before class starts.

Collaborative Coding Activity (25 min)

Have students work together to complete a coding activity that uses while loops, for loops, and/or nested iteration. Ideally, the students should design this program from scratch. They should think about a problem to be solved, describe it as an algorithm, and select the appropriate iteration structure. It is important to emphasize that the workload must be shared and each individual must make a contribution to the project within each group. Have students document an iterative design process: start with a general idea, break it into subparts, try it out, redesign, change and refine until you have explored a variety of creative options. The reflection journal at the end will comment on the group dynamics and problem solving used to create a positive group work environment.

Wrap Up (5 min)

Journal: In your journal, summarize the process that you used with your classmates to create the collaborative project. What was your original plan or algorithm? How did you use selection and iteration? What problems did you encounter? How did each group member contribute? What was the quality of the group dynamics? What concepts need to be clarified? How would these programs be changed if they were for widespread distribution rather than for personal use?


Options for Differentiated Instruction

  • Give students a copy of the guided activity instructions so they can follow along.
  • Possibly give students a code stem to work from for the collaborative project (while ensuring that they have the opportunity to problem-solve by thinking about and implementing an appropriate loop structure).

Evidence of Learning

Formative Assessment

Various checking-for-understanding techniques:

  • Temperature checks
  • Teacher reviews of student's code
  • Thumbs up/ thumbs down
  • Questioning throughout the lesson (whole group / small group / individual)

Quick quizzes

Peer review

Interactive journaling

Summative Assessment

Students will work collaboratively to develop a program that uses nested iteration and turtle graphics.