Math lesson plan · 6th grade (Year 7 in England) · 45 minutes
Surface area of cubes and cuboids
Geometry
CCSS 6.G.A.4England: KS3 Geometry and measuresEngland: GCSE Foundation Geometry and measures
Objective and success criteria
Students will: Surface area of cubes and cuboids.
- I can answer questions on today's skill on my own, without help.
- I can explain each step and say why it works.
- I can check my answer and spot a mistake.
Before and after
Needs first: Surface area using nets
Leads to: the next skill in this area.
Materials: Rulers and protractors, Squared or dotted paper, Shape cut-outs, Mini whiteboards and pens, Printed student sheet (below).
Warm-up · 5 min
- Quick retrieval from earlier learning (Surface area using nets). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- What is the surface area of a cuboid 5 m × 8 m × 5 m, in m²? → 210Prompt: A cuboid has 6 faces in 3 matching pairs.
- A cube has edges of 10 cm. What is its total surface area, in cm²? → 600Prompt: A cube has 6 identical square faces.
- What is the surface area of a cuboid 5 ft × 4 ft × 6 ft, in ft²? → 148Prompt: A cuboid has 6 faces in 3 matching pairs.
Hook · 5 min
- Show a photo of a building, a tile pattern or a road sign and ask what shapes and angles students can spot.
- Share the objective: Surface area of cubes and cuboids. Read the success criteria together.
I do: model it · 10 min
- Work through the example out loud, saying why you do each step, not just what you do.
- Example: Find the surface area of a cuboid 4 cm long, 4 cm wide and 9 cm tall, in cm².
- Step 1: 4 × 4 = 16, 4 × 9 = 36, 4 × 9 = 36
- Step 2: 2 × (16 + 36 + 36) = 176 cm²
- Answer: 176
- Pause after each step and ask a student to say what comes next.
We do: guided practice · 10 min
- Do these together. Students try each step on whiteboards before you reveal it.
- Use the hints as prompts rather than giving the answer.
- Find the surface area of a cuboid 10 cm long, 9 cm wide and 3 cm tall, in cm². → 294Prompt: A cuboid has 3 pairs of matching faces.
- A cube has edges of 9 cm. What is its surface area, in cm²? → 486Prompt: A cube has 6 identical square faces.
You do: independent practice · 10 min
- Students work on the student sheet. Circulate and check the first two answers of every student early.
- Students who finish: write a question of their own for a partner, with the answer.
The 8 questions are on the student sheet below, with answers in the key.
Exit ticket · 5 min
- Two questions on their own. Sort answers into got it / nearly / not yet to plan the next lesson.
- A storage box with no lid is 9 dm long, 2 dm wide and 6 dm tall. How much card is needed to make it, in dm²? → 150Prompt: There is only ONE l × w face (the base).
- Find the surface area of a cuboid 3 cm long, 10 cm wide and 9 cm tall, in cm². → 294Prompt: A cuboid has 3 pairs of matching faces.
Watch out for
- Thinking a square turned on its corner is no longer a square.
- Reading the wrong scale on a protractor.
Support and stretch
Support
- Review first: Surface area using nets.
- Use concrete materials: rulers and protractors.
- Give the first step of each question, or a partly worked example to finish.
- Pair with a confident partner for the guided practice.
Stretch
- Explain a common mistake in writing and how to fix it.
- Write a word problem that uses today's skill, then solve a partner's.
Homework and more practice
Free online practice with hints and printable worksheets for this skill: eurekami.com/math/grade-6.
Free lesson plan from eurekami.com/lesson-plan-builder