a fligolo
Solidus.
a prime square
Algebra
Verticies
The term "googol" refers to the mathematical concept representing the number 10 raised to the power of 100, which is written as 10^100. The name was coined in 1938 by the American mathematician Edward Kasner, who asked his nine-year-old nephew, Milton Sirotta, to come up with a name for this large number. There is no "real name" for googol beyond its mathematical designation, but it serves as a way to illustrate the concept of very large numbers.
Solidus.
A sphere is the correct terminology.
the "number symbol" ( You know 'item # 4.')
A hemisphere would be the correct name.
hash
Prime factors
Octalthorp. Note that, in Britain the '#' sign is called 'hash' and isn't used as the number sign - we write 'No.' for number.
a prime square
Algebra
The name of the symbol is "pound sign" or "number sign". It is also known as an "octothorpe" or "hash symbol".
the largest number
The correct term is dividend. The number doing the dividing is the divisor and the answer is the quotient.