Computers work by adding binary numbers using circuits of “logic gates”. Instead of an electrical circuit, it is possible to build these logic gates out of domino circuits. A huge network of dominoes is able to add numbers together in the same way a computer processor would, only much slower.

## Equipment needed

Heavy rectangular dominoes (a few hundred should be enough for a class to build circuits on the desk); contact us for details of how you can borrow our set of 10,000 dominoes to build a full computer!

## Curriculum Topics Covered

Logic gates; Boolean logic; binary numbers and binary addition; problem solving

These Think Maths worksheets cover the basics of binary numbers, logic gates and how to build circuits out of dominoes. If you try to build these circuits, we recommend using the heavier style of dominoes as they fall more reliably than the lighter plastic ones. We’ve found that a group of four students with around 200 dominoes can design and build a “binary half-adder” circuit.

In October 2012, Matt Parker and some of the Think Maths team actually built a computer entirely from dominoes, as part of Manchester Science Festival. There’s a video of the event, which you can see below. The final version of this circuit involved 10,000 dominoes, took twelve people six hours to balance them all up and was able to add two four-digit binary numbers and automatically give the five-digit binary sum. Matt Parker also made a Numberphile video to explain the maths behind the Domino Computer.

The Think Maths team are available to run workshops in schools to help a class of students design and build their own domino circuits in groups. We also have 10,000 dominoes we can lend to schools if you would like to try building a large-scale circuit! Please contact us (info@think-maths.co.uk) for more information.