try this see if u can work it out

[dio]

yes multiples of 9 and its posted on the other site as well if u post there dont spoil it for them

 

[Gronk]

yes multiples of 9 and its posted on the other site as well if u post there dont spoil it for them

It is multiples of 9 but also the symbol changes randomly for every use. So whilst the answer is always 9, the symbol given is differnet for each attempt.

 

[The Engineers Room]

It is the magic of the number 9. There are hundreds of these symbol things around they all are based on the fact that the digits in the multiples of 9 add up to nine.

9 - 0 + 9
18 - 1 + 8
27 - 2 + 7
36 - 3 + 6
45 - 4 + 5
54 - 5 + 4
...etc