DADADEL
This math puzzle is straightforward but can stump even experienced problem-solvers. Here’s how it goes:
Start with 1000. Add 40. Add another 1000. Add 30. Add another 1000. Add 20. Finally, add 1000 and 10.
Most people quickly tally the numbers and assume the total is 5000. This difference arises because our brains process information rapidly, often missing small details.
To avoid the common mistake, let’s take it step by step:
- Start with 1000.
- Add 40: 1000 + 40 = 1040.
- Add 1000: 1040 + 1000 = 2040.
- Add 30: 2040 + 30 = 2070.
- Add another 1000: 2070 + 1000 = 3070.
- Add 20: 3070 + 20 = 3090.
- Add a final 1000: 3090 + 1000 = 4090.
- Finally, add 10: 4090 + 10 = 4100.
The correct result is 4100. Simple, right? So why do so many people think it’s 5000?
This puzzle highlights how cognitive shortcuts can mislead us. When doing quick calculations, our brain tends to group numbers in a way that can result in errors. Many people mentally total all the 1000s as 4000, then quickly add 40, 30, 20, and 10, often overshooting and arriving at 5000. This happens due to cognitive overload. Our brains start relying on shortcuts when overwhelmed with information, which leads to mistakes.
