# Maths Magic

A collection of mathematics resources which contain an element of mathematical magic. The resources can be used to help bring a little bit of magic into a lesson when exploring a variety of mathematical topics.

### Why Does That Work?

This activity describes a simple trick using a domino. I often adapt the trick by not asking the student to subtract 15. I ask for the number at this point, subtract the 15 myself and reveal the domino they started with. Later I reveal the full sequence of steps and ask the students to explain why the trick works. Some students will use examples to test out what is happening, others will head straight for algebra.

The lesson plan links to Numeracy Strategy material 'Mind readers' and 'What's the trick?' and suggests a variety of number tricks that can be explained using algebra. The teacher notes provides teaching suggestions, extensions and ways the material can be adapted.

### Maths Made Magic

A handbook full of magical mathematical tricks is intended for use in the classroom to help teach many basic concepts in mathematics in an engaging and entertaining way.

Accompanying each trick is a comprehensive description of how the trick is to be performed, what effect is attempting to be achieved and the mathematics behind why the illusion works.

A couple of my favourites are 'The movement control charm and the mathematics of vectors' on page 32 and 'A magic user's investigation of the mathematics of sine and cosine' on page 54. There are lots of activities so no doubt you will have favourites of your own.

### Manual of mathematical magic

Another great compendium of mathemagical activities that can be used in the classroom. 'Doing Fibonacci's Lightning Calculation' works well at secondary level and with upper primary school students whilst the 'Brain Control Experiment' will bamboozle students and colleagues alike and can be explained using some simple algebra. A video showing the trick can be seen here.

The resource contains many other great tricks, some you may have seen before and many new ones.

### The Six Card Puzzle

This puzzle asks the 'victim' to choose a number between 1 and 63. That number appears on some of the cards, but not on others. There are six cards in total. The number can be calculated by considering the cards which contain the number chosen by the 'victim' - but how do you find the number so quickly?

The puzzle is based on binary numbers and the fact that any number can be uniquely expressed as the sum of powers of 2. This trick can often be found in Christmas crackers (if buy ones which are cheap enough!)

### Performing Number Magic A9

A set of very simple tricks ideal for younger students. Consecutive sums is a good introductory puzzle before moving on to Fibonacci adding up. I like calendar as it is a simple trick which students can easily master and can easily explain with links to work seen on a number grid. Performing number magic is the teachers guide with suggestions on how the resources can be used in class. It also explains the tricks, but don't read that bit yet, have a go yourself first!