Roman Countdown

Countdown in Roman numerals: combine six tiles with + − × ÷ to get as close as you can to the target before the clock runs out

New round options
Level
Clock
Players
TARGET?

Score

Round 1
Scoring: exactly on the target 10 points; within V (5), 7 points; within X (10), 5 points.
Convert: what the letters are worth
I1
V5IV = 4
X10IX = 9
L50XL = 40
C100XC = 90
D500CD = 400
M1000CM = 900

Add the letters from left to right, except that a smaller letter just before a bigger one is taken away: XIV = 10 + 4 = 14, XLII = 40 + 2 = 42, MCMXCIX = 1000 + 900 + 90 + 9 = 1999.

How to play

Six tiles are dealt as Roman numerals. The target stays hidden until you press Start the clock (or Reveal the target with no clock). Tap a tile, an operation, then another tile to combine them. The answer becomes a new tile you can use. You don't have to use all six, and each can only be used once.

Every step must give a whole number above 0 that can be written as a numeral (up to MMMMCMXCIX, 4999): no fractions, no negatives, no 0. Declare when you're as close as you can get; the best solution is then shown in numerals and in ordinary numbers.

When the clock runs out you hear a short beep (🔔 / 🔕 beside the clock turns it off; your choice is remembered on this device).

Show your working (on unless you turn it off): you type the result of each step in numerals before the new tile is made.

Show numbers also writes each numeral as an ordinary number, for anyone still learning to read them. With it off, you have to convert in your head.

Keys: 1–9 pick a tile, + - * / the operation, Backspace undoes, Enter declares.