Trainers

The trainers in Exercises: how they work and what they are for.

“Calibrator”

A run has five questions about quantities you come across in life and at work. In the time you have, you can’t work out or recall the exact value, so your answer isn’t a single number but a range: from one number to another.

The aim is for the true value to fall inside your range almost every time, while your ranges stay as narrow as possible. A range that’s too narrow often misses the true value. One that’s too wide catches it, but an answer like that doesn’t say much.

Once you answer, the true value is marked on the scale. Below it you can see whether it fell inside your range and the accuracy of your answer.

When people are asked for a range that will almost certainly contain the true value, it actually lands inside noticeably less often than they expect, because people are usually overconfident in their estimates. What this trains is calibration: setting a range as wide as your knowledge really allows.

“Three Colours”

The board has twelve numbered tiles and three colours. Each colour has a sum and a number of tiles: colour exactly that many tiles with it, so that their numbers add up to its sum. Two tiles are left over. A colour is complete when it has the right number of tiles and the right sum.

Tap a colour to select it, then tap a tile to give it that colour. Tiles that no longer fit the selected colour dim. You can also take a tile from another colour: it moves over to the one you’ve selected.

Every puzzle has exactly one solution.

This trains mental arithmetic and working through the possibilities: which numbers add up to the sum you need, and what that leaves for the other colours.

“Balloons”

A run is ten balloons. Each tap on the balloon inflates it by one breath; keep your finger on it and it keeps inflating. A swipe to scroll the screen does not inflate it. The breaths gather in the bank above the balloon.

“Take” takes the bank: the balloon flies off and the next one comes at once. You also see how much this balloon had to give — “Took 12 of 18”, for example.

If a balloon bursts, its breaths are lost. When it will burst is never shown in advance: every balloon has a limit of its own.

This trains stopping in time while the risk grows: deciding that enough is enough before everything is lost. A rule like “always tap so many times” does not work here — you have to look at the balloon.

“What changed?”

Figures appear on the field for a few seconds. Remember them before the bar above the field runs out. Then the figures hide and the field comes back: maybe something on it has changed, maybe nothing.

Mark the tiles where something changed and tap “Check”. The game never says how many changes there are. If nothing changed, mark nothing. An answer is right only when every changed tile is marked and no other tile is.

After the check, the changed tiles flip back and forth: how they were, how they are. A green ring means a tile marked right; a red one, a tile marked by mistake or a change missed.

A mistake does not end the run: it has as many steps as the settings say.

This trains visual memory: how much can be held from a single glance, and how precisely. Psychologists use a similar task to measure how many objects a person remembers after a brief showing.