The document instructs the reader to add 40, 1000, 30, 1000, 20, 1000, and 10 to the number 1000 without writing anything down or using a calculator, and provides the total sum of 4100.
1. Don't cheat and write it down or use a calculator
until you try it in your head!
Take 1000 and add :
40
1000
30
1000
20
1000
and 10
What is the total ? 4100