Math worksheet for estimating radicals on a number line.
Worksheet titled "Finding Radicals on a Numberline" with 10 problems, each showing a number line and a radical expression to estimate its position.
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Step-by-step solution for: Estimate square roots worksheet
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Show Answer Key & Explanations
Step-by-step solution for: Estimate square roots worksheet
Let's solve each problem step by step. The goal is to estimate the square root of a number and determine which letter on the number line best represents that value.
We’ll use perfect squares as reference points to estimate the radicals.
---
- Perfect squares near 133:
- √121 = 11
- √144 = 12
- So, √133 is between 11 and 12.
- 133 is closer to 144 than 121 → so √133 ≈ 11.5 or slightly more.
- On the number line: A=6, B=7, C=9, D=12 → Wait! This number line goes from 6 to 12 with marks at 6,7,8,9,10,11,12.
- But the points are labeled:
- A at 7
- B at 8
- C at 9
- D at 12
Wait — this seems off. Let’s recheck:
> Number line: 6 → A (at 7), B (at 8), C (at 9), D (at 12)
But √133 ≈ 11.5 → should be near 11.5, but the only point above 9 is D at 12.
So the closest point is D, since 11.5 is closer to 12 than to 9.
✔ Answer: D
---
- √121 = 11, √144 = 12 → √135 is between 11 and 12.
- 135 is closer to 144 → √135 ≈ 11.6
- Number line: 9 to 15, with:
- A at 10
- B at 12
- C at 13
- D at 14
- 11.6 is between 10 and 12 → closer to 12 → so B at 12 is the best choice.
✔ Answer: B
---
- √121 = 11, √144 = 12 → √132 ≈ ?
- 132 is closer to 121? No: 132 - 121 = 11, 144 - 132 = 12 → actually closer to 121?
Wait: 132 - 121 = 11, 144 - 132 = 12 → yes, closer to 121 → so √132 ≈ 11.5?
But let’s compute better:
Try 11.5² = 132.25 → very close!
So √132 ≈ 11.49 → just under 11.5
Number line: 10 to 16
- A at 11
- B at 12
- C at 13
- D at 15
So √132 ≈ 11.5 → halfway between 11 and 12 → A is at 11, B is at 12 → 11.5 is midway → but since it’s slightly less than 11.5, maybe closer to 11?
Wait: 11.5 is exactly halfway → but 11.49 is almost 11.5 → still closer to 12?
No: 11.5 is midpoint → 11.49 is very close to 11.5, so equally close to 11 and 12, but since the options are discrete points, and 11.49 < 11.5, it's closer to 11.
But let’s check:
- Distance from 11.49 to 11 = 0.49
- Distance to 12 = 0.51 → so closer to 11
So A at 11 is better.
But wait — is A at 11? Yes.
So √132 ≈ 11.49 → closer to 11 than 12 → choose A
✔ Answer: A
---
- √9 = 3, √16 = 4 → √12 is between 3 and 4
- Try 3.4² = 11.56, 3.5² = 12.25 → so √12 ≈ 3.46
- Number line: -1 to 5
- A at 1
- B at 3
- C at 4
- D at 5
So √12 ≈ 3.46 → between 3 and 4 → closer to 3 or 4?
- Distance to 3: 0.46
- Distance to 4: 0.54 → so closer to 3 → B at 3
✔ Answer: B
---
- √81 = 9, √100 = 10 → √92 between 9 and 10
- 9.5² = 90.25, 9.6² = 92.16 → so √92 ≈ 9.59
- Number line: 4 to 10
- A at 4
- B at 5
- C at 8
- D at 9
Wait — D is at 9? But √92 ≈ 9.59 → between 9 and 10 → but no point at 10? Only up to D at 9.
Wait — look again:
> Number line: 4 → A(4), B(5), then 6,7,8,9,10 → C at 8, D at 9
Wait: C at 8, D at 9 → but √92 ≈ 9.59 → which is greater than 9, but no point beyond 9.
But D is at 9 → and next is 10, but not labeled.
But 9.59 is between 9 and 10, and the only point at 9 is D.
So even though it's greater than 9, the closest marked point is D at 9, unless there’s a point at 10?
Wait — the number line shows:
```
4 5 6 7 8 9 10
A B C D
```
Wait — no: labels:
- A at 4
- B at 5
- C at 8
- D at 9
But 9.59 is after 9, so D is at 9 → but 9.59 is closer to 10 than to 9?
- Distance to 9: 0.59
- Distance to 10: 0.41 → so closer to 10
But there is no point at 10 — only D at 9.
So we must pick among existing points.
- D is at 9 → distance 0.59
- C is at 8 → distance 1.59 → much farther
So D is the closest point.
Even though 9.59 is closer to 10, 10 is not a labeled point, so D is the best available.
✔ Answer: D
---
- √64 = 8, √81 = 9 → √67 between 8 and 9
- 8.2² = 67.24 → so √67 ≈ 8.19
- Number line: 6 to 12
- A at 6
- B at 8
- C at 9
- D at 11
So √67 ≈ 8.19 → between 8 and 9 → closer to 8?
- Distance to 8: 0.19
- Distance to 9: 0.81 → so much closer to 8
→ B at 8
✔ Answer: B
---
- √36 = 6, √49 = 7 → √45 between 6 and 7
- 6.7² = 44.89, 6.71² = ~44.9 → so √45 ≈ 6.71
- Number line: 4 to 10
- A at 7
- B at 8
- C at 9
- D at 10
Wait — A is at 7? But √45 ≈ 6.71 → so between 6 and 7 → but A is at 7, and no point at 6.
So points:
- A at 7
- B at 8
- C at 9
- D at 10
So 6.71 is less than 7, so closest point is A at 7
Distance: |6.71 - 7| = 0.29
Next is B at 8 → 1.29 → much farther
So A is closest.
✔ Answer: A
---
- √16 = 4, √25 = 5 → √17 between 4 and 5
- 4.1² = 16.81, 4.2² = 17.64 → so √17 ≈ 4.12
- Number line: -1 to 5
- A at -1
- B at 2
- C at 3
- D at 4
Wait — D is at 4? But √17 ≈ 4.12 → so just above 4
Points:
- D at 4
- C at 3
- B at 2
- A at -1
So √17 ≈ 4.12 → closest to D at 4 (distance 0.12)
Is there a point at 5? No — only up to D at 4.
So D is the closest.
✔ Answer: D
---
- √81 = 9, √100 = 10 → √83 between 9 and 10
- 9.1² = 82.81, 9.2² = 84.64 → so √83 ≈ 9.11
- Number line: 8 to 14
- A at 9
- B at 12
- C at 13
- D at 14
So √83 ≈ 9.11 → very close to 9 → A at 9
Distance: 0.11 → very small
Other points are farther.
✔ Answer: A
---
- √100 = 10, √121 = 11 → √103 between 10 and 11
- 10.1² = 102.01, 10.2² = 104.04 → so √103 ≈ 10.15
- Number line: 7 to 13
- A at 8
- B at 9
- C at 10
- D at 12
So √103 ≈ 10.15 → between 10 and 11 → closest to 10?
- Distance to 10: 0.15
- Distance to 11: 0.85 → so closer to 10
C is at 10 → so C
✔ Answer: C
---
1. D
2. B
3. A
4. B
5. D
6. B
7. A
8. D
9. A
10. C
---
| # | Answer |
|---|--------|
| 1 | D |
| 2 | B |
| 3 | A |
| 4 | B |
| 5 | D |
| 6 | B |
| 7 | A |
| 8 | D |
| 9 | A |
| 10| C |
Let me know if you'd like a visual explanation or estimation method!
We’ll use perfect squares as reference points to estimate the radicals.
---
1) √133
- Perfect squares near 133:
- √121 = 11
- √144 = 12
- So, √133 is between 11 and 12.
- 133 is closer to 144 than 121 → so √133 ≈ 11.5 or slightly more.
- On the number line: A=6, B=7, C=9, D=12 → Wait! This number line goes from 6 to 12 with marks at 6,7,8,9,10,11,12.
- But the points are labeled:
- A at 7
- B at 8
- C at 9
- D at 12
Wait — this seems off. Let’s recheck:
> Number line: 6 → A (at 7), B (at 8), C (at 9), D (at 12)
But √133 ≈ 11.5 → should be near 11.5, but the only point above 9 is D at 12.
So the closest point is D, since 11.5 is closer to 12 than to 9.
✔ Answer: D
---
2) √135
- √121 = 11, √144 = 12 → √135 is between 11 and 12.
- 135 is closer to 144 → √135 ≈ 11.6
- Number line: 9 to 15, with:
- A at 10
- B at 12
- C at 13
- D at 14
- 11.6 is between 10 and 12 → closer to 12 → so B at 12 is the best choice.
✔ Answer: B
---
3) √132
- √121 = 11, √144 = 12 → √132 ≈ ?
- 132 is closer to 121? No: 132 - 121 = 11, 144 - 132 = 12 → actually closer to 121?
Wait: 132 - 121 = 11, 144 - 132 = 12 → yes, closer to 121 → so √132 ≈ 11.5?
But let’s compute better:
Try 11.5² = 132.25 → very close!
So √132 ≈ 11.49 → just under 11.5
Number line: 10 to 16
- A at 11
- B at 12
- C at 13
- D at 15
So √132 ≈ 11.5 → halfway between 11 and 12 → A is at 11, B is at 12 → 11.5 is midway → but since it’s slightly less than 11.5, maybe closer to 11?
Wait: 11.5 is exactly halfway → but 11.49 is almost 11.5 → still closer to 12?
No: 11.5 is midpoint → 11.49 is very close to 11.5, so equally close to 11 and 12, but since the options are discrete points, and 11.49 < 11.5, it's closer to 11.
But let’s check:
- Distance from 11.49 to 11 = 0.49
- Distance to 12 = 0.51 → so closer to 11
So A at 11 is better.
But wait — is A at 11? Yes.
So √132 ≈ 11.49 → closer to 11 than 12 → choose A
✔ Answer: A
---
4) √12
- √9 = 3, √16 = 4 → √12 is between 3 and 4
- Try 3.4² = 11.56, 3.5² = 12.25 → so √12 ≈ 3.46
- Number line: -1 to 5
- A at 1
- B at 3
- C at 4
- D at 5
So √12 ≈ 3.46 → between 3 and 4 → closer to 3 or 4?
- Distance to 3: 0.46
- Distance to 4: 0.54 → so closer to 3 → B at 3
✔ Answer: B
---
5) √92
- √81 = 9, √100 = 10 → √92 between 9 and 10
- 9.5² = 90.25, 9.6² = 92.16 → so √92 ≈ 9.59
- Number line: 4 to 10
- A at 4
- B at 5
- C at 8
- D at 9
Wait — D is at 9? But √92 ≈ 9.59 → between 9 and 10 → but no point at 10? Only up to D at 9.
Wait — look again:
> Number line: 4 → A(4), B(5), then 6,7,8,9,10 → C at 8, D at 9
Wait: C at 8, D at 9 → but √92 ≈ 9.59 → which is greater than 9, but no point beyond 9.
But D is at 9 → and next is 10, but not labeled.
But 9.59 is between 9 and 10, and the only point at 9 is D.
So even though it's greater than 9, the closest marked point is D at 9, unless there’s a point at 10?
Wait — the number line shows:
```
4 5 6 7 8 9 10
A B C D
```
Wait — no: labels:
- A at 4
- B at 5
- C at 8
- D at 9
But 9.59 is after 9, so D is at 9 → but 9.59 is closer to 10 than to 9?
- Distance to 9: 0.59
- Distance to 10: 0.41 → so closer to 10
But there is no point at 10 — only D at 9.
So we must pick among existing points.
- D is at 9 → distance 0.59
- C is at 8 → distance 1.59 → much farther
So D is the closest point.
Even though 9.59 is closer to 10, 10 is not a labeled point, so D is the best available.
✔ Answer: D
---
6) √67
- √64 = 8, √81 = 9 → √67 between 8 and 9
- 8.2² = 67.24 → so √67 ≈ 8.19
- Number line: 6 to 12
- A at 6
- B at 8
- C at 9
- D at 11
So √67 ≈ 8.19 → between 8 and 9 → closer to 8?
- Distance to 8: 0.19
- Distance to 9: 0.81 → so much closer to 8
→ B at 8
✔ Answer: B
---
7) √45
- √36 = 6, √49 = 7 → √45 between 6 and 7
- 6.7² = 44.89, 6.71² = ~44.9 → so √45 ≈ 6.71
- Number line: 4 to 10
- A at 7
- B at 8
- C at 9
- D at 10
Wait — A is at 7? But √45 ≈ 6.71 → so between 6 and 7 → but A is at 7, and no point at 6.
So points:
- A at 7
- B at 8
- C at 9
- D at 10
So 6.71 is less than 7, so closest point is A at 7
Distance: |6.71 - 7| = 0.29
Next is B at 8 → 1.29 → much farther
So A is closest.
✔ Answer: A
---
8) √17
- √16 = 4, √25 = 5 → √17 between 4 and 5
- 4.1² = 16.81, 4.2² = 17.64 → so √17 ≈ 4.12
- Number line: -1 to 5
- A at -1
- B at 2
- C at 3
- D at 4
Wait — D is at 4? But √17 ≈ 4.12 → so just above 4
Points:
- D at 4
- C at 3
- B at 2
- A at -1
So √17 ≈ 4.12 → closest to D at 4 (distance 0.12)
Is there a point at 5? No — only up to D at 4.
So D is the closest.
✔ Answer: D
---
9) √83
- √81 = 9, √100 = 10 → √83 between 9 and 10
- 9.1² = 82.81, 9.2² = 84.64 → so √83 ≈ 9.11
- Number line: 8 to 14
- A at 9
- B at 12
- C at 13
- D at 14
So √83 ≈ 9.11 → very close to 9 → A at 9
Distance: 0.11 → very small
Other points are farther.
✔ Answer: A
---
10) √103
- √100 = 10, √121 = 11 → √103 between 10 and 11
- 10.1² = 102.01, 10.2² = 104.04 → so √103 ≈ 10.15
- Number line: 7 to 13
- A at 8
- B at 9
- C at 10
- D at 12
So √103 ≈ 10.15 → between 10 and 11 → closest to 10?
- Distance to 10: 0.15
- Distance to 11: 0.85 → so closer to 10
C is at 10 → so C
✔ Answer: C
---
✔ Final Answers:
1. D
2. B
3. A
4. B
5. D
6. B
7. A
8. D
9. A
10. C
---
✔ Answer Key:
| # | Answer |
|---|--------|
| 1 | D |
| 2 | B |
| 3 | A |
| 4 | B |
| 5 | D |
| 6 | B |
| 7 | A |
| 8 | D |
| 9 | A |
| 10| C |
Let me know if you'd like a visual explanation or estimation method!
Parent Tip: Review the logic above to help your child master the concept of approximate square root worksheet.