Binary expansion is the process of representing a number in base 2, using only two digits - 0 and 1.
Binary expansion uses a base of 2, while decimal expansion uses a base of 10. This means that binary numbers only use 0s and 1s, while decimal numbers can use any digit from 0 to 9.
Hexadecimal expansion is the process of representing a number in base 16, using 16 distinct symbols - 0 to 9 and A to F.
Hexadecimal expansion is useful because it can represent large numbers using few digits. It is also commonly used in computer programming, as it is easier to convert between binary and hexadecimal than between binary and decimal.
To convert a binary number to a hexadecimal number, divide the binary number into groups of four digits and then replace each group with its corresponding hexadecimal symbol. For example, the binary number 10110010 would be divided into 1011 0010 and converted to B2 in hexadecimal.