Describe a Solid Made from Smaller Solids
Use the supplied layer description.
About 15 minutes, plus any extended practice
Supplied materials
- Paper and a pencil; drawing and spoken explanations are welcome. An adult may read directions and options aloud.
- Supplied worked-case record: A model has two layers, each with three cubes in a row.
- All quantities and shape descriptions are supplied in the worked example and questions; no purchase or personal information is needed.
Learn the idea
A solid model can be composed of matching cubes. Count every cube, including cubes in the stated hidden layer. The number of component cubes describes the model’s construction; it is different from the number of flat faces on one cube.
Use the supplied layer description. Draw or list the cubes in one layer and repeat for each stated layer. Count components without counting a shared boundary or a visible face as another cube.
Use the supplied full-layer count even when a sketch hides a cube. A cube’s faces are not separate component cubes. Represent each layer as its own row of cube labels.
- Represent each layer as its own row of cube labels.
- Follow the worked example. Point to each number or shape feature and say what it tells you.
- Use the supplied layer description.
- Try the question and then the three practice questions. Check your answers and explain any change you make.
See the method in action
A model has two layers, each with three cubes in a row. There are six cubes: three below and three above. Only some faces may be visible in a sketch, but the stated two full layers include all six components. The cubes’ faces are not extra cubes. Use the supplied full-layer count even when a sketch hides a cube. A cube’s faces are not separate component cubes. Represent each layer as its own row of cube labels.
Check your reasoning
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Helpful tips
- Use the supplied full-layer count even when a sketch hides a cube.
- A cube’s faces are not separate component cubes.
See the answer and explanation
4
Count the cubes in both complete layers. The result is 4.
Take it further
Three layers of four cubes use 12 cubes. Draw or explain all three layers.
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More practice: try new cases
Choose an answer for each problem. Explain your method on paper, then use the feedback to decide what to revisit.
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Check the subject sources
These LifeStarter passages, scenarios and exercises are authored for this Academy with AI assistance and review. External resources keep their publishers’ terms. A grade label suggests a starting level; it does not establish alignment with your school’s complete requirements.