Lesson 9: Nested Loops with Frozen

Overview

Now that students know how to layer their loops, they can create so many beautiful things. This lesson will take students through a series of exercises to help them create their own portfolio-ready images using Anna and Elsa's excellent ice-skating skills!

Purpose

In this series, students will get practice nesting loops while creating images that they will be excited to share.

Beginning with a handful of instructions, students will make their own decisions when it comes to creating designs for repetition. They will then spin those around a variety of ways to end up with a work of art that is truly unique.

Objectives

Students will be able to:

• Describe when a loop, nested loop, or no loop is needed.
• Recognize the difference between using a loop and a nested loop.
• Break apart code into the largest repeatable sequences using both loops and nested loops.

Preparation

Heads Up! Please make a copy of any documents you plan to share with students.

Vocabulary

• Loop - The action of doing something over and over again.
• Repeat - Do something again

Teaching Guide

Warm Up (15 min)

Introduction

Ask the class to discuss the last set of puzzles.

• What did they like/dislike?
• Which puzzles were hard? Why?
• Which puzzles were easy? Why?
• If you were to teach nested loops to a friend, what would you say to help them understand?

If there's time, give an introduction to the main characters of today's puzzles, Anna and Elsa from Frozen. Give the class the sister's back story if the class doesn't already know. To build excitement, tell the class they will be using nested loops to make some fantastic drawings with Anna and Elsa's ice skates!

Main Activity (30 min)

Course E Online Puzzles - Website

This set of puzzles is set up as a progression. This means every puzzle builds a foundation for the next puzzle. Students will enjoy making more and more interesting designs by making small and simple changes to code they have already written.

Wrap Up (15 min)

Journaling

Having students write about what they learned, why it’s useful, and how they feel about it can help solidify any knowledge they obtained today and build a review sheet for them to look to in the future.

Journal Prompts:

• What was today’s lesson about?
• How did you feel during today’s lesson?
• When do you use a loop? When do you use a nested loop?
• Thought exercise: Can you make everything a nested loop can with just a normal loop? Can you draw out an example?
• Answer: Yes, you can, but it is a lot more difficult. Nested loops make programs simpler.

Standards Alignment

CSTA K-12 Computer Science Standards

AP - Algorithms & Programming
• 1B-AP-11 - Decompose (break down) problems into smaller, manageable subproblems to facilitate the program development process.
• 1B-AP-13 - Use an iterative process to plan the development of a program by including others' perspectives and considering user preferences.