Square of 3-digit number which is near to multiple of 100

Square of 3-digit number which is near to multiple of 100

Lets say, we want to calculate the square of 608. The entire steps are illustrated in the following figure.
https://www.hamaraguru.com/assets/files/2018-01-12/1515752121-680943-imgur-31.jpeg
Steps for better understand:
Step 1: On Base 600, given number 608 is 8 more than 600. Add 8 and 608, the result is 616.
Step 2: Multiply 616 with base 6. The result is 3696. This is the 1st part of the answer. Which is left side part.
Step 3: Find the square of 8, the result is 64. This is the 2nd part of the answer.
The final answer is 369664

More examples to understand:
https://www.hamaraguru.com/assets/files/2018-01-12/1515752322-70856-imgur-32.jpeg
https://www.hamaraguru.com/assets/files/2018-01-12/1515753421-966877-imgur-33.jpeg