# The Journey Inside℠: Instructional Strategies

**Unit Summary**

In the prior unit, Circuits and Switches, students learned how binary numbers 0 and 1 are represented in electrical states (on/off). In the Digital Information unit, students learn how binary numbers can actually be used to create a language and logic for digital devices.

- Understanding some of the ways computers represent, process, and display letters, numbers, sounds, and images
- Comparing the binary number system to the decimal number system
- Adding binary numbers

- Using binary numbers to represent the alphabet (ASCII)
- Decision-making with AND/OR statements

**Goals and Objectives**

Students will learn:

- How the binary system can be used to represent images
- What a pixel is and how it's used to represent images
- How the two-state (on and off) nature of transistors can be used to represent information
- How to convert decimal numbers to binary numbers and vice versa
- How to add binary numbers
- How to represent letters of the alphabet with the 8-bit ASCII code

**Time to Complete Online Lessons:** about 50 minutes

**Preparation**

- Read the background information.
- Review and prepare for supplemental lesson ideas and group activities.
- Organize materials and equipment:

- Student computers with an active Internet connection

- Copies of the student handouts for this unit that you plan to use

- Printouts of the interactive whiteboard images (optional)

**Procedures**

- Have students complete the online activities:

Throughout the unit, facilitate the development of new vocabulary introduced in this unit. - Students who are not at the computer can work on supplemental lesson ideas and group activities.
- After students complete the online materials, they can:

- Demonstrate their knowledge of the one-to-one correspondence between binary-counting numbers and decimal-counting numbers by completing the table of values online or in the Binary Numbers Student Handout

- Perform simple addition problems between two binary numbers, and check their answers
- Suggest a list of other items that can be represented by a binary system, such as the possible answers in a yes/no survey, a true/false test, a game of 20 questions, and so forth
- Explain in their own words why ASCII code is used and what it's used for

**Student Handout**

**Computers and Pictures**

This handout teaches students:

- How the on/off state of transistors relates to the binary number system used by computers to store numbers, words, sounds, and pictures
- How computer display screens are made of tiny dots called pixels
- How simple pictures can be created in a grid using 1s and 0s to indicate which grid squares are colored in and which are not

**Binary Numbers**

This handout teaches students how to count in binary numbers and how to add them.

**Binary Counter**

Use this handout to direct a group activity where small groups of students use their bodies to form a binary counter to represent numbers from 0-15.

**ASCII Computer Code**

Using a chart of all letters and their binary code this handout helps students:

- Understand how letters of the alphabet can be expressed by binary numbers
- Write their name in ASCII code
- Write and translate secret messages written in ASCII

**Decision Making**

This handout teaches AND/OR logic, showing students how binary numbers can be used to represent yes/no and determine outcomes to simple statements.

**Interactive Whiteboard Images**

The images linked below are pertinent to this unit. You can project the images on an interactive whiteboard and use them in class discussions or activities.