Lesson 5.65.6 Small Group · Group 1
Start hereWords, worked example, and sentence starters
Learning target With my small group, I can find the surface area of a solid by using its net — one step at a time, with support.
Start hereWords for this lesson
Read each word before you begin. Say it out loud.
| Word | What it means | Example |
|---|---|---|
| Surface areaSpanish: Área de superficie | The total area of all the flat sides of a solid. | A box 6 × 4 × 2: SA = 2(24) + 2(12) + 2(8) = 88 in² — like wrapping paper needed |
| NetSpanish: Plantilla (desarrollo plano) | A flat shape that folds up into a solid. | unfolded box |
| FaceSpanish: Cara | One flat side of a solid shape. | a cube has 6 faces |
| Two-dimensionalSpanish: Bidimensional | A flat shape with length and width, but no thickness. | a net on paper |
| EdgeSpanish: Arista | The line where two flat sides of a solid meet. | A cube has 12 edges — the lines where two flat faces connect |
| PyramidSpanish: Pirámide | A solid with one base and triangular sides that meet at a point. | square base + 4 triangles |
How it worksWorked exampledrawing a net from a solid's attributes
These numbers are not on your problems. The steps are. Follow them with your own numbers.
A triangular prism has 2 triangle bases and 3 rectangular side faces. Draw and describe its net.
- List the attributes. bases: 2 triangles side faces: 3 rectangles
- Draw the 3 rectangles in a row — these wrap around the outside.
- Attach 1 triangle to the top edge of the row and 1 to the bottom edge.
- Check: five flat pieces, and every folding edge has a partner.
Answer: The net is a row of 3 rectangles with a triangle on the top edge and one on the bottom.
Now you trySame steps, your turn
The steps are the same as the worked example. The numbers are yours. Do the work.
A square pyramid has a square base and 4 triangular faces that meet at one point. Draw its net.
- List the attributes. base: square side faces: triangles
- Draw the base shape first, near the middle of your page.
- Attach one triangular face to each side of the base, folding outward.
- Check: total flat pieces Any overlaps?
Say it and write itSentence starters
Finish each sentence out loud with a partner. Then use them in your writing.
- This solid has faces shaped like .
- The net needs flat pieces because .
- I attached each to a side of the .
- When the net folds up, the meets the .
Word bank netfacefoldunfoldbasepyramidprismcubetrianglesquarerectangletwo-dimensionalthree-dimensional
Watch outA common mistake
A common mistake in Surface Area Using Nets is finding the area of only one face from each of the 3 matching pairs and forgetting to double it, instead of counting all 6 faces. For a box that is 9 in × 4 in × 5 in, a student might add just one face from each pair: (9×4) + (9×5) + (4×5) = 36 + 45 + 20 = 101 in², but the net actually has two of each face, so the correct total is 2(36) + 2(45) + 2(20) = 72 + 90 + 40 = 202 in² — exactly double. Before you submit, ask: 'Did I count both matching faces in each pair, or only one from each pair?'
Lesson 5.65.6 Small Group · Group 1
Group 1Supported practice
Learning target With my small group, I can find the surface area of a solid by using its net — one step at a time, with support.
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1Complete each step, then write the final answer.
A box is 6 in long, 3 in wide, and 2 in tall. Use its net to find its surface area.
- 1What is the area of the top and bottom together?
- 2What is the area of the front and back together?
- 3What is the area of the left and right together?
- 4Add the three pairs. What is the surface area?
Final answer: -
2Complete each step, then write the final answer.
A cube net has 6 equal squares. A cube has edges of 4 cm. Use its net to find its surface area.
- 1What is the area of one square face?
- 2How many faces does the net show? Are they the same size?
- 3Multiply. What is the surface area?
Final answer: -
3Complete each step, then write the final answer.
A box is 5 cm long, 2 cm wide, and 1 cm tall. Find its surface area.
Show your workHint Find the area of each pair of faces. Then add the three pairs.
Final answer: -
4Complete each step, then write the final answer.
A box is 9 in long, 6 in wide, and 4 in tall. Find its surface area.
Show your workHint The box has 3 pairs of matching faces. Find one face in each pair, then double it.
Final answer: -
5Complete each step, then write the final answer.
A cereal box is 8 in wide, 3 in deep, and 12 in tall. How much cardboard covers the whole box with no overlap?
Show your workHint Cardboard covers every face, so find the surface area. Think of the net: 3 pairs of faces.
Final answer: -
6Complete each step, then write the final answer.
Jin finds the surface area of a box that is 7 cm by 4 cm by 2 cm. He writes 28 + 14 + 8 = 50. Is he right? What is the surface area?
Show your workHint Count the faces on a net of a box. How many faces did Jin add?
Final answer:
Explain your thinkingWhy does the net of a box have 3 pairs of matching faces? Use Jin's mistake to explain.
Sentence starter Each face has a matching face because ___. · Jin's answer is too small because ___.