3D Building Blocks
Count blocks and visualise 3D structures from different angles.
What is 3D Building Blocks?
3D building block questions show you a structure made of small cubes (blocks). You might be asked to count the total number of blocks, identify what the structure looks like from a different angle, or work out how many blocks are hidden from view.
These questions test your spatial awareness – your ability to “see” three-dimensional objects in your mind and understand their structure.
Step-by-Step Method
Count layer by layer
Start with the bottom layer and count systematically. Then count the next layer up, and so on.
Account for hidden blocks
Blocks on top must have blocks underneath them. If you see a block on the second layer, there must be one below it too.
Consider different views
Think about what the structure looks like from the front, the side, and the top. Each view shows a different arrangement.
Draw if it helps
Sketch the view from the angle requested. Mark which blocks would be visible from that direction.
Worked Examples
A structure is made of cubes: bottom layer has 4 cubes in a square (2×2), top layer has 1 cube in the front-left position. How many cubes in total?
Working
- Bottom layer: 4 cubes (2×2 square).
- Top layer: 1 cube.
- Total: 4 + 1 = 5 cubes.
A structure of cubes is shown from the front: it looks like a staircase going up from left to right (1 block, 2 blocks, 3 blocks high). The structure is only 1 block deep. How many cubes?
Working
- Column 1: 1 cube high = 1 cube.
- Column 2: 2 cubes high = 2 cubes.
- Column 3: 3 cubes high = 3 cubes.
- Structure is 1 block deep, so total = 1 + 2 + 3 = 6 cubes.
You see a structure from the front showing 3 cubes in an L-shape. What might it look like from the right side?
Working
- The L-shape from the front: 2 cubes stacked vertically on the left, 1 cube on the bottom-right.
- From the right side, you would see the single cube on the bottom and possibly the stacked cubes behind it.
- If the structure is 1 block deep, from the right you would see 1 cube (the right column) and the 2-high column behind it.
Common Mistakes
Forgetting to count blocks that are hidden behind other blocks.
If a block is stacked on top of another, the one underneath must exist even if you cannot see it.
Miscounting when blocks are arranged in an irregular pattern.
Count systematically: go layer by layer from bottom to top, or column by column from left to right.
Top Tips
- Always start counting from the bottom layer and work upwards.
- A block on the second layer means there must be a block below it on the first layer.
- Use building blocks or sugar cubes at home to practise building and viewing structures.
- When asked about views from different sides, imagine walking around the structure.
- Check that your count matches the visible faces – every visible face belongs to exactly one block.
Ready to practise?
Put these techniques into action with our free practice papers.
Practise Non-Verbal Reasoning Questions