This is the state of American education

[Greyblades]

I'm presuming thats a language problem, a square number is any number that is the result of a number multiplied by itself, or squared.

5*5 =25
4*4 = 12
3*3 =9
2*2 = 4
1*1 = 1
20000*20000 = 400,000,000
25, 12, 9, 4, 1 and 400,000,000 are all square numbers.
It's generally assumed that anyone over 13 in a english speaking country's education system has at least an idea what a square number is.