Mathematics Made Simple Part 3

Please go to Mathematics Made Simple and Mathematics Made Simple part 2 before you read this blog because this is one step further.

Another brain training session again, I do hope that everybody who have read the first and second session find it interesting and helpful.

Let’s go straight to the point without further ado.

Add 1-10. Please give me the answer immediately without having to use calculator or computer. The answer is 55. This time we have to use a simple formula to get the answer immediately.

Formula:

N = number of digit, in this case 10 digits

N/2 (N+1)
= 10/2 (10+1)
= 5(11)
= 55

Add 1-40. Again no calculator or computer is allowed. Please give me the answer immediately. The answer is 820. You may use the computer to test it later.

N = number of digit, in this case 40 digits.

N/2 (N+1)
= 40/2 (40+1)
= 20(41)
= 820

I learned this technique from my ex boss aged 70 when I was working for his company.

Stay tuned to this blog, if you want to challenge yourself to more difficult level of mathematics made simple in my next session.

Happy learning!