A problem by Ahmed Salah

It can also be as...5 is only missing from first 9 natural numbers...and its 10/2..

It is just a magic square.When we sum up the numbers horizontally,vertically or diagonally the answer would be 15.

it's a 3 x 3 magic square.

so, in every row or column ,the value will be=(1+2+3+...................9)/3

                                                                   =45/3=15

so, the wanted value will be, 15-(9+1)=5

IF ADD 5 IN EMPTY PLACE THEN ADDITION IS COMING 15 IN EACH ROW AND EACH COLUMN SO ANS IS 5

we can see from the left up corner we have 2 and right down corner we have 8, so 2+8=2. This condition happen also with 9+1=10 and etc. So the "?" is the mean of 2+8 which is 5

5 IS THE MISSING NUMBER

All the three numbers sum up to 15. that's why $5$ must be the digit at the center.

The sum of the numbers in any row vertical or horizontal or diagonal = 15 so, the answer is "5"