Let's solve the
"Estimating Area" worksheet step by step.
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🔷 Problem 1: Estimate the area of irregular shapes
Each square represents
1 cm², so we count full squares and estimate partial squares.
We use the
"counting squares" method:
- Full squares → count as 1
- Partial squares → if more than half, count as 1; less than half, ignore or count as 0.5 (approximate)
Let’s go through each shape:
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####
a) First shape (top left)
We’ll count the number of full and partial squares.
Looking at the shape:
- It covers approximately
36 full squares
- There are several partial squares around the edges.
- Estimating partials: about
8–10 half-squares, which is roughly
4–5 extra cm²
✔ Estimated area: ~40–42 cm²
Let’s go with a reasonable estimate:
👉
41 cm²
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####
b) Second shape (top right)
This one is elongated and curved.
- Count full squares: ~32
- Partial squares: ~10–12, mostly over half → add ~5–6
- Total: ~37–38 cm²
👉
38 cm²
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####
c) Third shape (bottom left – fish-like)
Looks like a fish.
- Full squares: ~28
- Partial squares: ~10–12, many are more than half → add ~5–6
- Total: ~33–34 cm²
👉
34 cm²
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####
d) Fourth shape (bottom right – arrow-like)
Pointy and open at bottom.
- Full squares: ~30
- Partial squares: ~8–10 → add ~4–5
- Total: ~34–35 cm²
👉
35 cm²
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✔ Answers for Problem 1:
| Shape | Estimated Area |
|-------|----------------|
| a) |
41 cm² |
| b) |
38 cm² |
| c) |
34 cm² |
| d) |
35 cm² |
*(Note: These are estimates — slight variations are acceptable depending on how you count partial squares.)*
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🔷 Problem 2: Draw an irregular shape to represent given areas
Each square =
10 cm²
So:
- For
180 cm²: Need
18 squares (since 18 × 10 = 180)
- For
350 cm²: Need
35 squares (since 35 × 10 = 350)
You must draw
irregular shapes that cover exactly these numbers of squares.
#### 🎯 Instructions:
- Use the grid provided.
- Draw any irregular shape (not a rectangle or regular polygon).
- Make sure it covers
18 squares for the first, and
35 squares for the second.
- You can make them wavy, zigzag, etc., but ensure they fill the correct number of squares.
#### Example ideas:
-
For 180 cm² (18 squares): Draw a squiggly snake-like shape covering 18 squares.
-
For 350 cm² (35 squares): Draw a larger blob or spiral covering 35 squares.
> ⚠️ Since this is a drawing task, I can't draw it here, but you can do it on paper:
>
> - In the
left grid, draw any irregular shape covering
18 squares.
> - In the
right grid, draw any irregular shape covering
35 squares.
> - Make sure no overlaps or gaps outside the shape.
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✔ Summary of Answers
####
1. Estimate the area:
a)
41 cm²
b)
38 cm²
c)
34 cm²
d)
35 cm²
####
2. Draw shapes:
- Left grid: Draw any irregular shape covering
18 squares → represents
180 cm²
- Right grid: Draw any irregular shape covering
35 squares → represents
350 cm²
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Let me know if you'd like me to generate a visual sketch description or help with a specific counting method!
Parent Tip: Review the logic above to help your child master the concept of irregular shapes worksheet.