How do you remember the difference between a squared number or prime number?

Answer 1

I can't give a good way to remember prime numbers based on their name, but for square numbers, you can just remember it as a figure:

You can think of numbers as a collection of dots, so

1 = *

2 = * *

3 = * * *

etc.

Now, if you form a square with n dots on the side, the number of dots in the square will be n^2. This is why they are called "square numbers". For instance:

1^2 = 1

*

2^2 = 4

* *

* *

3^2 = 9

* * *

* * *

* * *

etc.

So the number n^2 is the number of dots in the square with n dots on each side. The ancient Greeks were into this kind of representation of numbers and devoted much study to what are called "figurate numbers", meaning "numbers that can be represented by a figure". In particular, they looked at triangular numbers, rectangular numbers, and pentagonal numbers, in addition to what I just showed you with square numbers.

Getting back to your original question, remember square numbers as the number of dots in a *square* of dots. As for primes, if you are having issues with only primes and squares, just remember it as "not square numbers".