Question

What will be the sum of all the numbers written in the highlighted region of the calendar?

Answer 1

The numbers to be added can be written in the format shown here.

Now, it can be observerd that the blocks with same colour has a number added to 10 in one box and the same number is subtacted from 10 in the other block.

So, the number in each block can be considered as 10.

Therefore, the sum of all the numbers written in the highlighted region of the calendar = 10 $\times$ 9 = 90