The image above presents a simple math puzzle. It asks you to solve a series of additions using only your mind. It says: You have 1000, add 40, add 1000, add 30, again 1000, add 20, add again 1000, and finally 10. What is the result? This is a classic brain teaser. It is designed to trick your brain into making a common mistake.
The Common Mistake
Most people who try to solve this in their head quickly arrive at the answer 5000. They add the thousands together and get 4000. Then they add the smaller numbers, 40, 30, 20, and 10, and get 100. Then they add 4000 and 100 together and get 5000. But that is not the correct answer.
The Correct Answer
The correct answer is 4100. Let us break it down step by step.
Start with 1000.
Add 40: 1040.
Add 1000: 2040.
Add 30: 2070.
Add 1000: 3070.
Add 20: 3090.
Add 1000: 4090.
Add 10: 4100.
The answer is 4100.
Why People Get It Wrong
This puzzle works because of a cognitive trick. When you add the numbers in your head, your brain tends to round the intermediate sums. For example, after adding 1000, 40, and 1000, you might mentally round 2040 to 2000. Then you add 30 and get 2030, which you might round to 2000 again. This rounding causes you to lose track of the smaller numbers. By the end, you have rounded away the 100, and you are left with 5000 instead of 4100.
The Bottom Line
This puzzle is a fun way to test your mental math skills. It shows how easily our brains can be tricked by numbers. The next time you try a puzzle like this, take your time and write it down if you can. Or just be aware of the rounding trap. The correct answer is 4100.
Did you get the right answer? Share this puzzle with your friends and see if they can solve it.
