Computer Science • Number Systems
Hexa-Tac
Enemies fall from orbit carrying a binary or denary code. Type the matching hexadecimal digit(s) before they reach your platform — miss, or let one land, and space command loses a life.
Learning objectiveNumber systems · base conversion
Convert between binary, denary and hexadecimal quickly and accurately, including recognising the hexadecimal equivalent of a given binary or denary value on sight.
By the end of a round you should be able to: convert a 4-bit binary value to a single hex digit without working it out on paper; convert an 8-bit binary value to a two-digit hex byte; convert a denary value in either range straight to hex; and do all of this fast enough to matter, since the whole point of hexadecimal is that it's a shorter, easier-to-read stand-in for binary.
- Each enemy's code is shown in binary or denary — chosen at random, and marked with a small ₂ (binary) or ₁₀ (denary) so it's never ambiguous.
- Type the hex digit(s) that match a falling enemy's code — in 4-bit mode a single key fires instantly; in 8-bit mode the shot fires once you've typed two digits.
- Use keys 0–9 and A–F, or tap the on-screen keypad.
- Typing a code with no matching enemy currently on screen wastes the shot and costs a life — check before you shoot.
- An enemy that reaches your platform also costs a life. You start with 5.
- The barrage speeds up the longer you survive.