JaGaiMo

Rebuilt around 99 stages. All 7,321 solvable boards are sorted by how many solutions they have and how heavy the sums are, so each stage really is harder than the last.

Use each of five dice exactly once to hit a target number.

■ How it works

The target sits at the centre of the board as two black dice. A 5 and a 20 means you are aiming for 25. Build four expressions from the five dice around it, using each die once, and land on 25.

An answer can be carried into the next expression. The order and the operators are yours to choose. Some boards fall to addition alone; others cannot be reached without division.

■ Three ways to play

• TIME ATTACK — race the clock, with your times on Game Center
• COUNTDOWN — solve inside the stage's allowance
• PRACTICE — pick any stage you have reached, with no clock at all

■ 99 stages

Boards are not drawn at random. All 9,072 combinations of five dice and a target were solved ahead of time, and the 7,321 that have a solution are sorted by difficulty into 99 stages.

Difficulty is not just how many solutions a board has. It also measures how heavy those solutions are to compute — which operators they need, how large the numbers get, whether an addition carries. Two boards with the same number of solutions land in different stages if one needs only addition and the other demands division.

Early stages come from boards with hundreds of solutions. The last stage holds boards with one or two.

■ When you are stuck

Four tools, bought with coins:

• Hint — fills a single row, chosen from solutions that fit the dice you have already placed, so it works on a half-built board
• Rewind 10s / Freeze 15s / Reset the clock — COUNTDOWN only

Tools that touch the clock are limited to COUNTDOWN so that the TIME ATTACK leaderboard stays worth something.

■ Solver

Enter any board and it lists every solution. Useful for checking an answer, or for finding out whether a board can be solved at all.

■ Game Center

Leaderboards for time attack points, countdown points, clear speed and clear count.