Why is this strange thing is necessary and for whom can base 256-ary numeral system be useful "de facto"? _{(Not for the second class)}

Unknown bin, oct, dec, hex and their 'neighbors', or about whatever form of the number will you use by writing, the quantity of apples will not change. _{(Already for the second class)}

What is the binary row and why is it necessary?

Transfer binary numbers to decimal numeral system and back.

Transfer binary numbers to octal numeral system and back.

Transfer binary numbers to hexadecimal numeral system and back.

How are numbers in the base 256-ary numeral system written?

Transfer numbers from base 256-ary to binary numeral system and back.

Transfer numbers from base 256-ary to hexadecimal numeral system and back.

Transfer numbers from base 256-ary to octal numeral system and back.

Transfer numbers from base 256-ary to decimal numeral system and back.

Let's talk about BCD-system.