Answer:
steps below
Step-by-step explanation:
This is not a fresh game, you can find it everywhere on the web. The basic trick to fill 3x3 square with consecutive numbers is put the middle number at the middle box and all the row, column or diagonal sum should be 3 x that number. Here is 3 x 7 = 21.
So 3,4,5,6, 7 ,8,9,10,11
