Mathematics for IGCSE & O level - Estimation (Section 1)
1
What is the purpose of the instruction, “When rounding to estimate, the answer should not be a greater degree of accuracy than any of the values used in the calculation.”?
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A
C
D
2
What should you do before calculating a problem with estimation?
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(A)
Round the numbers.
3
In the context of Estimation what is the main benefit?
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(B)
To make a quick and simple calculation
4
Which of the following are useful tools for the process of estimation?
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A
D
5
When you round a number to 2 significant figures, what digit in the original number determines if you round up or down?
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(C)
The digit to the right of the second digit
6
What are the key steps involved in rounding to significant figures?
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A
C
7
What is the rule for the digit after the last significant figure?
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(D)
Both A & B
8
What is the purpose of estimating in a real-world problem?
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(A)
To save time and simplify calculations.
9
If a number is 0.047 and you are asked to round to 1 significant figure, what would be the correct answer?
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(A)
0.04
10
When estimating the sum of 12.7, 3.14, and 5.9, what would be a sensible first step?
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(C)
Round each number to the nearest whole number.
11
Which of the following are good times to use estimation?
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(A)
When a quick result is needed.
12
Which of the following are reasons for the use of estimation?
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A
B
D
13
Which of the following should be considered when performing calculations?
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A
C
14
When should you consider using estimation?
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(A)
When a quick approximate answer is needed.
15
What is the best approach to estimate the total cost of 7 items that cost $3.89 each?
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(B)
Round each item to $4 and multiply.
16
What would you do with the number 17.63 when rounding to 2 decimal places?
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(B)
Round to 17.63
17
If you measure the length of a table to 1.234 meters, which option would have the most significant figures?
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(D)
1.234 meters
18
When dealing with significant figures, what is the purpose?
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(C)
To indicate the accuracy of the number.
19
Why are zeros used in a number when finding significant figures?
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(B)
To maintain place value
20
What is the main focus of the topic of Estimation?
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B
C
21
Which are important aspects of a correct calculation?
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B
C
D
22
In estimation, why do we round the values before performing calculations?
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(A)
To make the calculation easier.
23
Which is an example of when it would be suitable to estimate?
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(C)
Estimating the cost of groceries
24
What does the accuracy depend on in an estimation?
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(A)
The original values.
25
What do we call the numbers that contribute to the precision of a measurement?
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(C)
Significant figures
26
Why is estimation a good tool to use?
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(B)
To simplify complicated math problems
27
What rule needs to be followed when rounding to significant figures?
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(C)
Look at the digit to the right.
28
What is the primary goal of estimation?
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A
B
29
You measured the length and width of a table as 1.84m and 1.52m. The correct area of the table is?
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(C)
2.8 m²
30
What is the main purpose of estimation?
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(A)
To give a quick answer.
31
Which of the following are reasons to round values?
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A
C
32
Which of the following could be classified under “Estimation”? (Select all that apply)
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A
B
D
33
How is estimating often useful?
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(C)
In day-to-day activities
34
If rounding a number to 2 decimal places, what is the maximum value that can be in the 3rd decimal place before you round up?
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(A)
4
35
How can estimating help in everyday life?
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(B)
Help budget spending.
36
Which one of these scenarios would need estimation?
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(C)
The approximate cost of a dinner out
37
Which of the following is the most appropriate way to estimate the height of a lamp post if the height of an adult person is 1.7m?
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(B)
Estimate the lamp post's height to be about four times the height of the adult person.
38
If a building's height is approximately 20 meters and you want to estimate the height of a tree next to it, what do you need to know?
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(C)
The tree's height is relative to the building.
39
When rounding 0.00487 to 2 significant figures, what is the result?
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(D)
0.005
40
When rounding to a given number of decimal places, the digit immediately to the right of the required decimal place must be...
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(C)
Greater than or equal to 5
41
If asked to round 36.78 to 2 significant figures, what would be the answer?
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(C)
37
42
In the number 0.0509, which digit is the first significant figure?
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(B)
5
43
What are the main things that have to be considered when working to a sensible degree of accuracy?
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A
C
D
44
When estimating, why might it be important to consider the context of the problem?
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(A)
To determine the appropriate level of accuracy.
45
In estimation, what does 'significant figures' primarily tell you?
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(B)
How accurate a number is.
46
What is the purpose of using significant figures?
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(C)
To reflect the precision of a measurement.
47
In what situation is estimation more useful than an exact calculation?
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(A)
When the calculation is complex.
48
What is the first step when estimating a solution?
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(C)
Round values
49
If you are estimating the height of a tree next to a building, which strategy is most helpful?
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(B)
Compare the building's height to the tree.
50
If a measurement is given as 12.345 meters and you need to express it to 3 significant figures, what would the result be?
