Hexadecimal as Binary Shorthand
Writing four bits as one of sixteen digits, so long binary values can be read and typed by people without anything being lost.
What a learner can do afterwards
- Convert between binary and hexadecimal in groups of four bits
- Convert a two-digit hexadecimal number to decimal
- Point at a place hex actually shows up, such as a colour code
1 · Read
Hexadecimal is shorthand for binary, and it is how colour codes you meet on web pages are written. It uses sixteen digits: 0 to 9, then A, B, C, D, E and F stand for 10 to 15. Four bits make exactly sixteen patterns, so one hex digit always stands for four bits.
Split binary into groups of four starting from the right, padding the left group with zeros if it is short. The group 1010 becomes A and 0110 becomes 6, so 10100110 becomes A6. Your turn: 11011110 splits into 1101 and 1110, which is DE.
Going back is just as easy: write each hex digit as its four bits. To reach decimal, multiply each digit by its power of 16 and add, so 2F is 2 times 16 plus 15, which is 47. Colour codes are one place you meet hex in real life.
Always group from the right, never the left. Padding belongs on the front of the short left group.
Four bits per hex digit, grouped from the right, with nothing lost either way.
2 · Watch
Take it off screen
Where it sits
8 questions wait behind this lesson, each with its answer explained. Every answer feeds the sky: stars light as they are learned, and dim when it is time to come back.