# Lesson plan – Converting hexadecimal to binary and denary ## Lesson Overview

In this lesson, students will be introduced to hexadecimal as a way for humans to more easily represent large binary numbers. Students will also be shown how to convert from hexadecimal to denary to binary and back again.

This lesson is suitable for students who already have a basic understanding of binary numbers but no experience of hexadecimal numbers is necessary.

For all conversion tasks, the first four challenges are mandatory, however, the second four tasks are optional extension activities for advanced students.

No equipment is required.

##  Lesson Objectives

Students will be able to:

• Understand why hexadecimal is used
• Convert 8-bit binary numbers to hexadecimal
• convert 2-bit hexadecimal numbers to binary

### Materials and Prep

• Slideshow – Hexadecimal to binary conversion (see below)
• Students will require pen and paper
• Conversion handouts
• Students will require access to a computer with an internet connection

### Vocabulary

• Binary – base 2 numbering system
• Hexadecimal – base 16 numbering system
• Denary – base 10 numbering system
• Number systems – a way of expressing or writing numbers
• Bit – a unit of information in computing

### Summary

• Introduction – 5 minutes
• Binary recap – 5 minutes
• Hexadecimal Introduction – 5 minutes
• Binary to hexadecimal conversion activity – 5 minutes
• Hexadecimal to binary conversion activity – 5 minutes
• Plenary – 5 minutes

#### Introduction (5 minutes)

Students are introduced to the lesson through the binary numbers magic trick. After a few examples of the trick, the teacher should explain to the students how it works and let them have a try.

#### Binary recap (5 minutes)

Students will have a basic knowledge of binary, and so a brief recap of what binary is should be sufficient. Students will refresh their learning by converting 4-bit and 8-bit binary numbers to denary.

Students should be asked to do increasingly more difficult conversions from binary to denary to demonstrate the difficulties of dealing with large binary numbers. Students are not expected to actually work out the conversions, only presented with the problem of a 16-bit conversion to understand its complexity. To then explain how many computers use 32-bit and 64-bit should ensure they understand why hexadecimal is needed.

#### Binary to hexadecimal conversion activity (5 minutes)

Students are provided with a conversion handout and tasked with converting 8-bit binary numbers to hexadecimal.

Extensions activity – students may choose to also convert 12-bit and 16-bit binary numbers, with or without the help of the handout

#### Hexadecimal to binary conversion activity (5 minutes)

Students are provided with a conversion handout and tasked with converting 2-bit hexadecimal numbers to binary.

Extensions activity – students may choose to also convert 3-bit and 4-bit hexadecimal numbers, with or without the help of the handout.

#### Plenary (5 minutes)

Students should have a basic understanding of how to convert hexadecimal to binary and back again. To practice, students can spend the last five minutes trying to get the highest score on Flippy Bit.