Train The Bases

A base, also known as radix, specifies the number of unique digits to represent a number.
The 3 most popular bases:
Decimal; base 10; uses digit 0 through 9.
Binary; base 2; uses digit 0 and 1.
Hexadecimal; base 16; uses digit 0 through 9 and A through F. (A = 10, B = 11,...., F = 15)

There are multiple ways to indicate which base is being used.
You can use a prefix; 0xC0 indicates a hexadecimal number; 0b11000000 indicates a binary number,...
You can use subscript; 192₁₀ indicates a decimal number; C0₁₆ indicates a hexadecimal number, 11000000₂ indicates a binary number,...

First write down the values of the powers of 2 from right to left until you reach the biggest value that fits in your decimal number.
Go down the line. Take the highest power of 2, check if it fits into your number.

If it does, write down a 1 and subtract it from your number. This is your new number.
If it doesn't, write a 0 and move on to the next power.
After subtracting, move on to the next power and keep going until your number reaches 0.

If you reached 0, you should have the correct binary number.

First write down the values of the powers of 2 from right to left above your number until you reach the end of it.

Add up all values that have a 1 under them.

That is it. You should have the correct decimal number.

Write down your number and split it into groups of 4 bits (a nibble) from right to left. You can add 0 to the front if you can't get an even amount.

Convert the value of each nibble into decimal numbers from left to right.
Write those values down from left to right until you are done.
Keep in mind that A = 10, ..., F = 15

This should give you the correct hexadecimal number.

Write down your number and split each digit.

Convert the value of each digit into a nibble from left to right.
Write those nibbles down from left to right until you are done.

This should give you the correct binary number.
(The images shows this conversion from bottom to top)

There are multiple ways to do this.
The simplest way is to convert the decimal number into binary, and convert the binary to hexadecimal.

There are multiple ways to do this.
The simplest way is to convert the hexadecimal number into binary, and convert the binary to decimal.