NCETM workshop - 12th March 2008. Professional Development Using Online Support, Utilising Rich Mathematical Tasks Liz Woodham Mark Dawes Jenny Maguire. [This is a PowerPoint version of the original SMART notebook]. The Project. Every teacher from 3 primary schools Initial training
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NCETM workshop - 12th March 2008
Using Online Support,
Utilising Rich Mathematical Tasks
[This is a PowerPoint version of the original SMART notebook]
How many different 3 digit numbers can you make from the digits 1, 3 and 5?
How many of these are prime numbers?
Use ITP Number Grid to find multiples and prime numbers
A number is divisible by:
it is an even number
the digits add to a multiple of 3
you can halve it and halve it again
the last digit is 0 or 5
it is even and the digits add to a multiple of 3
use a calculator
you can halve it three times
the digits add to 9
the last digit is 0
Can you make square numbers by adding 2 prime numbers together?
Try with the squares of numbers between 4 and 20
Do you discover any square numbers which cannot be made by adding 2 prime numbers together?
If you do can you think why these numbers cannot be made?
Explain how you tackled the investigation
Daniel and Milan
Tips: make a list of square numbers
We noticed that you had to add 2, 3 or 5 to most of the numbers
So we tried each of these numbers and worked out if the answer was a prime number and it worked!
If a square number is odd,
then if you take 2 away from it,
if that number isn't a prime number,
you can't add 2 numbers to make
When asked why, Oliver replied that
if it didn't work taking 2 away, the other prime numbers were odd
therefore you would get an even number, which wouldn't be prime
Genevieve, Tayler and Abi
First we tried random numbers which fitted the rules.
Then we found prime numbers close to the square and used littler prime numbers to fill the gaps.
When we got stuck we started thinking of number bonds
or asked for advice
Jessie and Hannah
For numbers over 100 we got a close odd number and found a prime number to go with it.
Then we checked to see if the first number was a prime number.
If the square number is odd you have to take away 2 and if that number is prime, it can be done.
If the square number is even it has to be odd + odd or even +even
Other strategies which children used