1. is exactly equal to which whole number?
- A4
- B5
- C6
- D7
Show answer
Answer: B) 5
5 x 5 = 25, so = 5.
Class 8 Estimating Square Roots — practice questions with answers
Squares and Roots · 5 sample questions from the school syllabus. Try each one, then open the answer and the worked solution.
2. Which whole number is nearest to?
- A8
- B9
- C10
- D11
Show answer
Answer: B) 9
9² = 81 and 10² = 100. 90 is closer to 81 than to 100, so is nearest to 9.
3. The value of is:
- A1.5
- B1.05
- C15
- D2.5
Show answer
Answer: A) 1.5
1.5 x 1.5 = 2.25, so = 1.5.
4. A square garden in Bhopal has area 156 square metres.
The gardener says the side is about 12.5 m. Check by squaring: which statement is true?
The gardener says the side is about 12.5 m. Check by squaring: which statement is true?
- A12.5² = 156.25, so the estimate is very good
- B12.5² = 150, so it is an underestimate
- C12.5² = 160, so it is an overestimate
- DSide is exactly 13 m
Show answer
Answer: A) 12.5² = 156.25, so the estimate is very good
12.5² = 156.25, which is extremely close to 156, so is approximately 12.5 m and the estimate is very good.
5. Anil claims is about 44.7. He checks using 44² = 1936 and 45² = 2025.
Which conclusion is correct about his estimate?
Which conclusion is correct about his estimate?
- AWrong; is between 43 and 44
- BCorrect; is between 44 and 45 and near 44.7
- CWrong; is exactly 45
- DWrong; is between 45 and 46
Show answer
Answer: B) Correct; is between 44 and 45 and near 44.7
Since 1936 < 2000 < 2025, is between 44 and 45. 44.7² = 1998.09, very close to 2000, so 44.7 is a good estimate.
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