Playing Games to Help with Maths
Me
Teach maths at secondary school at The High School of Glasgow
Volunteer for UKMT – mentoring and write questions for JMC/IMC
Teach all levels including top sets – spend lots of time on extension material
Help prepare maths students for University including Oxbridge
Playing Games to Help with Maths
Revision
Simple games can be used to deliver revision content
Playing Games to Help with Maths
Bingo
Playing Games to Help with Maths
19 8 12
Nine numbers from 1 to 20
Games
Use for investigation
Play against a pupil first to demonstrate
Don’t try too hard to link to maths
Wait for strategies to emerge
Doing anything well is maths
Playing Games to Help with Maths
21
Start counting at 1
Playing Games to Help with Maths
Say either one, two or three numbers, taking turns
Whoever says 21 loses
High-Low
Guess if the next card is higher or lower
Playing Games to Help with Maths
Ace is highest, then King, Queen, Jack, Ten
Also lose if you get a pair
Unlucky 6
Stand up
Playing Games to Help with Maths
Every time the dice is rolled add that number to your score
Sit down when you feel you have enough points
If a 6 is rolled and you are still standing you lose all your points
Nim
Make at least three piles of at least three objects
Playing Games to Help with Maths
On your turn take some or all objects – must all be from the same pile
Whoever takes the last object loses
Each card has eight symbols on it
Dobble
Every pair of cards has exactly one pair of symbols that matches
Just call it out to win!
Dobble – Rules
Have another go
Dobble – Rules
Dobble – Rules
Here is one variation of the game
Play in groups of three. �For each round one person is the referee and doesn’t play
1. The referee turns over two cards at the same time
2. The first person to name the matching symbol takes both cards
3. The referee replaces both cards
4. The person with the most cards at the end is winner and becomes the� referee next time
Dobble
Playing Dobble is easy – for ages 4+
Constructing a Dobble set is what is difficult
(and interesting mathematically)
Dobble – Golden Rule
The challenge is to arrange symbols so that they follow the Golden Rule
Every pair of cards matches with one and only one symbol
Dobble – Bad Sets
This Dobble set follows the Golden rule, but wouldn’t be much fun to play!
Every pair of cards matches with one and only one symbol
A
A
A
A
A
Dobble – Bad Sets
This Dobble set also follows the Golden rule, but wouldn’t work either�(each pair of cards has it’s own matching symbol)
Every pair of cards matches with one and only one symbol
A B�C D
B F �I J
A F �G H
C G �I K
D H �J K
A Dobble set with 57 cards would need over 1000 symbols
For a Dobble set with 5 cards you already need 10 different symbols.
Dobble – Perfect Sets
A good set has different matches between each pair, and not many symbols
Every pair of cards matches with one and only one symbol
A B
B C
A C
In fact, a ‘perfect set’ has as many different symbols as there are cards
Pictured is a perfect Dobble set with three cards and three symbols �(but still too small to be playable)
Dobble – Seven card set
The next perfect Dobble set is seven cards.
Every card has three symbols
There are seven symbols in total
Dobble – Seven card set
Example solution
A B C
A D E
A F G
B D F
B E G
C D G
C E F
It is possible to make a seven card set
just by writing down symbols
Dobble – Fano Plane
An alternative approach uses this �Fano Plane
Dobble – Fano Plane
Every circle is on three lines and��every line goes through three circles
A banana �B crab�C dog
D moon�E spiral�F candle
G cloud
1
2
3
4
5
7
6
A
Name Example
D
E
B
C
F
G
Fano Plane
A �B �C
D�E�F
G
1
2
3
4
5
7
6
A
1
2
3
7
4
5
6
Name
Fano Plane
1. Add letters B-G to circles in any order
2. Draw pictures for A-G at the top
3. Copy three pictures in to each numbered square based on what circles that numbered line is on in the Fano Plane
4. Cut out the squares and play Dobble
Dobble – Perfect Sets
Perfect Dobble sets
Symbols on each card | Cards | Symbols |
3 | 7 | 7 |
4 | 13 | 13 |
5 | 21 | 21 |
6 | 31 | 31 |
7 | 43 | 43 |
8 | 57 | 57 |
Can you spot the pattern?
In fact normal Dobble has 55 cards, not 57. Can anyone work out why?
Junior�Dobble
Normal�Dobble
Dobble – Larger Sets
Larger Dobble sets need a method to form them. �For example:
1. Extending the Fano Plane
2. A grid method
3. Double Latin Squares method
4. A projective geometry method
5. Computer Programming method
Dobble – Larger Sets #1 (Fano Plane)
Dobble – Larger Sets #2 (Grid Method)
x | x | x | x | | | | | | | | | |
x | | | | x | x | x | | | | | | |
x | | | | | | | x | x | x | | | |
x | | | | | | | | | | x | x | x |
| x | | | x | | | x | | | x | | |
| x | | | | x | | | x | | | x | |
| x | | | | | x | | | x | | | x |
| | x | | x | | | | x | | | | x |
| | x | | | x | | | | x | x | | |
| | x | | | | x | x | | | | x | |
| | | x | x | | | | | x | | x | |
| | | x | | x | | x | | | | | x |
| | | x | | | x | | x | | x | | |
Dobble – Larger Sets #3 (Double Latin Squares method)
Ad1G | Be1H | Cf1I |
Ce2G | Af2H | Bd2I |
Bf3G | Cd3H | Ae3I |
GHI x |
123 x |
ABC x |
def x |
Dobble – Larger Sets #4 (Projective geometry method)
A
A
A
B
B
B
C
C
C
A�B�C�x
d
d
d
e
e
e
f
f
f
d e f x
1
1
1
123x
2
2
2
3
3
3
G
G
G
H
H
H
I
I
I
GHIx
Dobble – Larger Sets #5 (Computer Programming method)
Output for N=4 (13 card set)
Dobble – Larger Sets #5 (Computer Programming method)
Output for N=5 (21 card set)
Dobble – Larger Sets #5 (Computer Programming method)
Output for N=6 (31 cards)
Dobble – Perfect Sets
Perfect Dobble sets
Symbols on each card | Cards | Symbols |
3 | 7 | 7 |
4 | 13 | 13 |
5 | 21 | 21 |
6 | 31 | 31 |
7 | 43 | 43 |
8 | 57 | 57 |
Junior�Dobble
Normal�Dobble
Minibridge
Played in pairs, with tricks and trumps
Optimal strategy a long way off, hope for sensible play only
Basic mnemonics – win with cheapest card that will win, lose with worst card
Some arithmetic, mostly strategy
Playing Games to Help with Maths