How Block Counting works
Each picture is a three-dimensional pile of identical blocks, some of them numbered. For each numbered block, you count how many other blocks it touches. Several questions share one pile.
The touching rule is strict: blocks touch only if all or part of their faces meet. Blocks that meet only at an edge or a corner do not count. Some faces are hidden from view, so you have to work out what lies underneath and behind from the shape of the pile.
It counts towards the Combat Systems Officer and Air Battle Manager composites.
Count in the same order every time
A fixed order stops you missing a face or counting one twice:
- Above: count the blocks resting on top of it.
- Below: count what it rests on. A block above the bottom layer usually sits across two blocks.
- Sides: check both ends and both long sides for blocks lying against it.
- Add the four directions together, and only then look at the options.
- Ignore blocks that meet only at a corner or an edge, however close they look.
Worked example
Block 3 lies in the middle layer of a pile. Two blocks lie across it from the layer above. It rests across two blocks in the layer below. One block lies end to end with it in its own layer, and the block beside it on the other side touches it only at a corner. Above 2, below 2, sides 1: block 3 touches 5 blocks. The corner-only block is the trap; counting it gives 6, which will be one of the options.
Tips for the real subtest
- Learn the pattern of the pile once, then answer all its questions. Several numbered blocks share each picture, so understanding the pile pays several times.
- A top-layer block has nothing above it, and a bottom-layer block nothing below; use that to save time.
- At 10 seconds a question, choose your best count and move on. There is no penalty for a wrong answer.
- Practise on a computer screen, where the whole pile is visible at the size you will see on test day.
Practise Block Counting on CogniPrep
Our Block Counting game gives you 30 questions in 5 minutes: six piles drawn by us, with five numbered blocks each and the block being asked about marked in blue. In our piles, blocks in a layer lie side by side and end to end, each layer is turned a quarter turn from the one below, and no block is completely hidden; real piles may be built differently. Your result is the number right, split by which layer the blocks you missed were in, compared with other CogniPrep users.