You will need:
2 dice and a pen and paper.
Take in turns to:
- Throw the dice
- From the dice, construct 2 or perhaps 3 numbers. For example, if you throw a two and a three, you can make 5, 23 and 32 (3+2=5, two followed by three is 23 and three followed by two is 32)
- Score one point for each prime number you have made (so this example scores one for the 5 and one for the 23, scoring two points in total).
- If you need to use a calculator, then a Casio fx-83GT PLUS can tell you whether a number is prime. This is *not* cheating – students will soon start to recognise the primes they need, rather than having to check using the calculator!
The Winner Is:
The person who has the most points.
Things to discuss:
- Why are two even numbers always such bad news? (even+even=even and the only even prime number is two)
- Is it possible to score three points with one throw?
- If there is a six in your throw, what happens?
This sample space diagram may help:
|
Sample Space Diagram for 2 Dice |
||||||
|
1 |
2 |
3 |
4 |
5 |
6 |
|
|
1 |
(1,1) |
(2,1) |
(3,1) |
(4,1) |
(5,1) |
(6,1) |
|
2 |
(1,2) |
(2,2) |
(3,2) |
(4,2) |
(5,2) |
(6,2) |
|
3 |
(1,3) |
(2,3) |
(3,3) |
(4,3) |
(5,3) |
(6,3) |
|
4 |
(1,4) |
(2,4) |
(3,4) |
(4,4) |
(5,4) |
(6,4) |
|
5 |
(1,5) |
(2,5) |
(3,5) |
(4,5) |
(5,5) |
(6,5) |
|
6 |
(1,6) |
(2,6) |
(3,6) |
(4,6) |
(5,6) |
(6,6) |
Maths Tutor Bournemouth 