Well done to those children who worked hard in the GD sessions this afternoon with me and earned a brick for your class! So here are the follow-up challenge questions:

What do you notice about the answers to the questions? Is there a pattern?

Will the answers ever end in the digits 3 or 7?

Can you list the prime numbers up to 50?

Can you write a similar challenge of your own?

1) The number pattern is 19, 29, 41, 55 and 71 because it has two nines and two ones but one five. I notice that it is asking us to solve 5 times 6 which equals 30 and it is telling us to solve 5 add 6 which equals 11. Then it is telling us to solve 30 add 11 which equals 41.

2) No, the numbers won’t end in 3 and 7 because the number pattern is continuous.

3) The prime numbers up to 50 are 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43 and 47.

4) The mathematicians are declaring that the answer to 6 times 6 is a prime number. True or false? Explain how you know.

The pattern was 19, 29, 41, 55 and 71 but it has two nines and two ones but one five. I think that the numbers 3 and 7 won’t end up being there because I think the pattern will repeat. Prime numbers up to 50 are 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43 and 47. Wavey the monster is working out 7 x 7. He thinks that it is a prime number. Is he correct? Why? Prove it in as many possible methods.

After calculating from 2 to 11, I noticed the pattern ends in 1,9,9,1,5,1,9,9,1

If I skip to 16 arrow 17 the pattern will also include a 5 just like, 6 arrow 7.

No, the answers will never end in 3 or 7.

The prime numbers up to 50 are 1, 2, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47.

My own challenge question is Bob is trying to work out 13 arrow 9. Is the answer a prime number below 50? Show your working out.

Super reasoning Nuha! The answer to your problem is 131 – a prime number but above 50. There is an error in your list of prime numbers – can you find it?

Thank you for answering my challenge. I realised that 1 is not a prime number as it does not have 2 factors.

The pattern was 19, 29, 41, 55 and 71 but it has two nines and two ones but one five. I think that the numbers 3 and 7 won’t end up being there because I think the pattern will repeat. Prime numbers up to 50 are 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43 and 47. Wavey the monster is working out 7 x 7. He thinks that it is a prime number. Is he correct? Why? Prove it in as many possible methods.

Great reasoning Miski! Look at your prime numbers list again – not quite right! To answer your question, 7×7=49 which is not a prime number as it has more factors than just itself and 1.