Thank you for your reply. In lesson 22, while trying to find the square roots. I found this problem. Attached is the practice problem I was talking about. Instead of using the digit sum method for checking, I tried to use the last figure method (attached). As you suggested, I can use the last figure method only when I know that it is a perfect square.
Can you please take a number which is not a perfect square and explain the remainder concept?
And one more request Ken, after the quiz, if we can know which question we have done wrong and what is the correct way, that would be really helpful. Because we are completing the quizzes, but we are not knowing which problem we have done wrongly and what is the correct answer for the same and the reasoning behind it. Thank you.