**Learning Objectives:**

- add two 8
**‐**bit binary integers and explain overflow errors which may occur

**Lesson 1: Theory (Binary Addition)**

Suggested time: 50 mins

**Starter:**

I started with a fun starter activity courtesy of Mark Ward via CAS called Binary Bingo. To download the activity, click here.

Each student was given a bingo card and numbers were picked at random using a free random name selector (see Classroom Management Tools). The first student to get a full house was the winner.

**Main:**

I began by writing a simple sum (adding to denary numbers together) on the board:

Next, I introduced a simple binary sum:

Next I explained that when we add two 1s we need to carry over to the next column. I demonstrated this using the following sum:

**.**

*overflow*Finally, I gave students a series of binary addition challenges courtesy of Chris Barnard via CAS. You can download the worksheet and answer sheet here: Binary Addition Exercise

**Extension:**

Students were directed to the following YouTube video explaining binary subtraction:

**Plenary:**

Students played the CISCO Binary Game: http://forums.cisco.com/CertCom/game/binary_game_page.htm

**Resources:**

*Useful resources:*

Binary Calculator – http://gwydir.demon.co.uk/jo/numbers/binary/add.htm

Binary Arithmetic Task - http://www.allaboutcircuits.com/worksheets/bin_math.html

**Lesson 2: Raspberry Pi - Python Challenge**

Suggested time: 50 mins

**Main:**

Students were instructed to setup their Raspberry Pis and to launch IDLE 3.

Students were then asked to attempt a series of introductory Python challenges courtesy of Tom Gilmour via CAS: http://community.computingatschool.org.uk/resources/332

*Alternative:*Alternatively, if you do not have access to a set of Raspberry Pis, students can still complete the Python challenges:

To install Python for FREE, go to the python.org website and download a standard installation of the latest version of Python. This will provide you with everything you need.