100.
It is called Hexadecimal
Counting in hexadecimal is basically like counting in decimal - just remember that the highest digit is "F" instead of "9". So, after "9", you continue with the digits "A", "B", ... "F", and after the last digit gets to "F", you set it back to zero (just as in decimal, you would set the last digit to zero after a "9"), and add one to the previous digit. For example, the next number after 3F is 40. And the next number after 3FF is 400.
Probably one that starts with "one, two, three, four, five".
21
How about: Four
100.
It is called Hexadecimal
Counting in hexadecimal is basically like counting in decimal - just remember that the highest digit is "F" instead of "9". So, after "9", you continue with the digits "A", "B", ... "F", and after the last digit gets to "F", you set it back to zero (just as in decimal, you would set the last digit to zero after a "9"), and add one to the previous digit. For example, the next number after 3F is 40. And the next number after 3FF is 400.
Fungi, fauna are two.
No - at least not in the English language. We have zero (starts with z) one (starts with o) two (starts with t) three (starts with t) four (starts with f) five (starts with f) six (starts with s) seven (starts with s) eight (starts with e) nine (starts with n) ten (starts with t) eleven (starts with e) twelve (starts with t) thirteen (starts with t) fourteen (starts with f) fifteen (starts with f) sixteen (starts with s) seventeen (starts with s) eighteen (starts with e) nineteen (starts with n) twenty (starts with t) thirty (starts with t) forty (starts with f) fifty (starts with f) sixty (starts with s) seventy (starts with s) eighty (starts with e) ninety (starts with n) from there on up, all numbers start with one of these, for example: 35,500,400,122 Thirty five billion five hundred million, four hundred thousand one hundred twenty-two (starts with T) We do have some number related words that we don't actually start the names of numbers with: Hundred Thousand Million Billion Trillion Quadrillion Quintillion Sextillion Septillion Octillion Nonillion Decillion Undecillion Duodecillion Tredecillion Quatrodecillion Virgintillion ... and so forth continuing to use the same types of prefixes with u (un), b(bi) d(duo,dec), t(tri), q(quad, quint), s(sex, sept), o(oct), n(non), c(cent), m(mili), None of them start with "J". The extremely large numbers Googol and Googleplex both start with G. The metric prefixes include kilo mega giga tera peta exa zeta yotta (none of which start with J) and fractional prefixes of deci centi milli micro nano pico femto atto zepto yocto (still nothing starting with J) Informally 10 to the 27th power is called "hella" - as sort of a nerd joke - but still no "J" number.
The highest numerical digit is 9, but hexadecimal follows that with letters going to F. So in hexadecimal, F would be the highest digit.
Tuesday! Why?
V sounds like it starts with a F, if that helps.
A game that starts with f is frisbe
Probably one that starts with "one, two, three, four, five".
One flying insect that starts with f is the Firefly.