Reckon Game

Reckon is a mental calculation puzzle with a memory twist. You get a few number tiles and a target, and you combine the tiles two at a time until you make the target exactly. The catch is that each new result shows its value for only a few seconds before it turns face down, so by the third step you are working with numbers you can only remember. It is the skill mental calculators train: holding running totals in your head while you work.

How to play

1. You get five or six number tiles and a target. Make the target exactly, using some or all of the tiles, each one once.
2. Each step: pick a tile, an operation (+ − × ÷) and another tile. The two are replaced by one new tile holding the result.
3. Whole numbers only. No negatives, no fractions and no 0, so ÷ works only when it divides exactly.
4. A new result shows for a few seconds, then turns face down. You have to remember what each face-down tile holds. The step log shows the tiles you combined, but never a result.
5. On Normal and Hard, a peek turns every tile face up for two seconds. Undo takes back the last step, as often as you like, and puts its two tiles back as they were.
6. Your score is your steps against the fewest possible, and your time. Next puzzle deals a new one at once, as many as you like. Change level goes back to the start.

Choose a level on the start screen. Easy has five numbers and a target from 10 to 99, and its results stay face up, so it has no peeks. Normal, the default, has six numbers and a target from 100 to 299, its results turn face down after three seconds, and it has two peeks. Hard has six numbers and a target from 300 to 999, its results turn after two seconds, the six numbers turn face down too after a ten-second preview, and it has one peek. The numbers come from 1 to 9 and 10, 15, 20 and 25. Every puzzle can be solved, in three steps at the fewest on Easy, four on Normal and five on Hard. On a keyboard, press 1 to 6 to pick a tile, + - * / to pick an operation, Backspace to undo and Space to peek on Normal and Hard. Escape pauses.

Scoring

Your score is the steps you took against the fewest possible, and your time, counted from the moment play starts. The two are kept apart, not blended into one number. Each level keeps its own records:

• your best time,
• how many puzzles you have solved,
• how many of them you solved in the fewest steps, and
• your longest run of puzzles solved without a peek.

Your records are saved in this browser only.

To hold your results as they turn over, give each one a word or a picture with the Major System, as in using the Major System for multiplication tables. Or try our other free memory games.