The German mathematician C Goldbach, in 1742, made the conjecture that every even number, except 2, was the sum of two prime numbers.
(A conjecture is an opinion without sufficient grounds, or an unproven rule.)
e.g. 7 + 5 = 12 (prime + prime = even)
Complete the following table to test this conjecture.
Can you find an even number that can not be found by adding two primes?
Why do you think it is a conjecture and not a rule?
The idea for this investigation came from The Maths' Connection published by Family Maths Trust