Basic Calculation: 06

Detailed Explanation: If a number is more than 50, then the question is how much it is more than 50? Both are added. As for example, in the square of 51; 51 is 1 more than 50, thus 1 is added to 51, so that total becomes 51 + 1 = 52. 
We take always half of the total, i. e. half of 52, which is 26. We read always 26 hundred and square of 1. That is, 2600 + 01 = 2601
Similarly, in the square of 52; 52 is 2 more than 50, thus 2 is added to 52, so that total becomes 52 + 2 = 54. 
We take always half of the total, i. e. half of 54, which is 27. We read always 27 hundred and square of 2. That is, 2700 + 04 = 2704. and so on.