Write number like this:
As in the calendar; mark four numbers in a square and find the difference of diagonal products. Is it the same for all squares of four numbers?
Let us consider this green square.
Diagonal products are:
2×8 = 16
7×3 = 21
Difference = 21-16 = 5
Now let us consider this green square.
Diagonal products: 9× 15 = 135
14× 10 = 140
Difference = 140 – 135 = 5
Now consider this green square.
Diagonal products: 11× 17 = 187
16× 12 = 192
Difference = 192 – 187 = 5
So, we observe that in all the above cases the difference of diagonal products is coming out to be same and is equal to 5.