Point - What times what equals 256?

It blows my mind that anybody can use a computer without learning about computer numbers.

A switch can be on or off -- two states. Two switches have four combinations. Each additional switch doubles the number of combinations. In a computer the switches are called bits. It takes seven bits to define the 128 printable characters, but it is preferred to have an even number, so everything in your computer uses 8 bits and that is called a byte. Two bytes make a word, four bytes make a doubleword, and some things use a lot more than that. For instance the memory uses 2, 4, or 8 bytes at a time, depending on how powerful it is. Floating point numbers are typically 10 bytes.

So back to the numbers:
1
2
4
8
16
32
64
128
256

This keeps on doubling. 10 bits have 1024 combinations, so 1024 is called K or kilo, an engineering abbreviation for "thousand". 20 bits gets you 1,048,576 combinations and that is called M or mega, abbreviation for a million. Now you know why a file size or hard disk size might be different numbers.

So if you play with these numbers for a while you eventually notice that 256 = 16^2.