A teacher in Tanzania asks his class:

“If you had 10 goats and a hyena came and ate 4, how many goats would you have left?”

One student raises his hand confidently: “None”

The teacher frowns almost angry, “None? but 10 minus 4 is 6.”

The student shakes his head :

“Sir, if a hyena comes for my goats, I am running away; I am not staying to count anything!”