Score
How to play
Choose six tiles one at a time from the two piles, or deal six. The target stays hidden until you press Start the clock (or Reveal the target with no clock): then it appears and the clock starts.
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. Declare when you're as close as you can get; a best solution is then shown, step by step.
Show your working (on unless you turn it off): you type the result of each step (on the keypad) before the new tile is made. After two tries you get a hint, after three you can ask to be shown.
Keys: 1–9 pick a tile, + - * / the operation, Backspace undoes, Enter declares.