Mysterious elevator

Mysterious elevator wraps a run of maths puzzles in a small story. You are trapped in a skyscraper of 100 floors, and the building is run by the Keeper of Numbers, a sarcastic character with a taste for mathematical riddles. The way out is down, one floor at a time, in a creaky old lift.

Every floor is a test. The main task is to swap blocks carrying numbers and signs until they form a correct equation, and the developer says other puzzles turn up along the way too. Floors range from plain arithmetic to what the developer calls logic traps.

Get it wrong and, in the developer's words, the elevator may crash. Get it right and you go down, closer to freedom. The whole thing is played with mouse clicks or taps in a tall portrait frame.

Each floor presents a set of blocks with numbers and mathematical signs. Click or tap the blocks to swap them around until they build a correct equation. Solve the floor and the elevator carries you lower. Watch for the extra puzzles that appear between equations, and take care, because a mistake may send the elevator crashing.

Before swapping anything, check what the equation has to say: work out which arrangement of numbers and signs makes it true, then move blocks into place. Since a mistake can crash the elevator, settle on the full equation in your head first rather than testing swaps one at a time.

An equation-building maths puzzle with a 100-floor story, played in a portrait frame. Input is mouse click or tap. Puzzles run from simple arithmetic to logic problems, and a wrong answer may end in a crash.

Stickman Mental Math also has you assemble an equation from numbers and signs, to reach a target number. Order of Operation Challenge tests whether you can solve expressions in the right sequence.