There is no way to calculate the value of 'f', since it is not part of an equation.
1, 2, 3, 4, 6, 12, F
Most keyboards have 12 function keys. F1-F12 (all the keys with the letter 'F' and then a number).
$3.00
Retail list is $5.00 in F-12
1,750$
The abbreviations G-4, F-12 & EF-40 are numismatic grades and can be used on any coin.
Assuming you mean Indian Head cent 1887 retail value is $6.00
Your gun was made in?æ1924. The F stands for field grade, and the 12 for 12 gauge. They value around $300.
12
Ctrl - SAlt - F - SF12 (Save As)Shift - F12 (Save)
Coin grades consist of broad categories designated by letters, and within each of those there are finer subcategories indicated by numbers. "F" stands for "Fine", a grade meaning moderate wear. Within the F grade there are 8 numeric levels ranging from 12 to 19. Thus an F12 is the lowest grade a coin can have within the Fine category and an F19 is the highest. A coin that's more worn than F12 falls into the VG (Very Good) or lower category, and a coin that's better than F19 becomes VF (Very Fine) or higher.
Coin grades consist of broad categories designated by letters, and within each of those there are finer subcategories indicated by numbers. "F" stands for "Fine", a grade meaning moderate wear. Within the F grade there are 8 numeric levels ranging from 12 to 19. Thus an F12 is the lowest grade a coin can have within the Fine category and an F19 is the highest. A coin that's more worn than F12 falls into the VG (Very Good) or lower category, and a coin that's better than F19 becomes VF (Very Fine) or higher.