Being Smart, sometime...

[Baimi]

Being Smart sometime take a longer time to solve a simple problem
and 聪明反被聪明误.

 

[jubilee1919]

The answer is

2581 = 2

 

[ZorrorroZ]

yes.. this is the same concept as the number of roses on the dice riddle.

The clue is "pre-school kids" with little or no concept of mathematics.

Thus, if you don't expect them to solve mathematically, the way they solve it is thru observation.

Therefore, if you observe the numbers in the above riddle, the answer is very clear.