This Harvard interview question is not about calculations, but about perspectives!

The interviewer writes "1()+8()=66" and asks you to fill in the number 1-9 to make the equation true.

At first glance, it seems incomprehensible, but the answer is to fill in 8 and 1 - because if you turn the numbers upside down, "99=88+11"!

Why does this question screen out top talent?

Break through the habitual thinking: Most people are obsessed with mathematical calculations, but ignore the possibility of "visual flipping".

Observational test: It can detect changes in the shape of numbers (e.

g., 6 is 9 upside down), reflecting the sensitivity of details.

Innovation: Harvard values the ability to solve problems using unconventional methods.

What was your first reaction? ➤ Stick to the calculations? It is possible to reach a dead end. ➤ Thinking of inverting numbers? Your mind is flexible enough!

Can you design a similar "visual number puzzle"?