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.”?
Answer
A
C
D
2
What should you do before calculating a problem with estimation?
Answer
(A)
Round the numbers.
3
In the context of Estimation what is the main benefit?
Answer
(B)
To make a quick and simple calculation
4
Which of the following are useful tools for the process of estimation?
Answer
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?
Answer
(C)
The digit to the right of the second digit
6
What are the key steps involved in rounding to significant figures?
Answer
A
C
7
What is the rule for the digit after the last significant figure?
Answer
(D)
Both A & B
8
What is the purpose of estimating in a real-world problem?
Answer
(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?
Answer
(A)
0.04
10
When estimating the sum of 12.7, 3.14, and 5.9, what would be a sensible first step?
Answer
(C)
Round each number to the nearest whole number.
11
Which of the following are good times to use estimation?
Answer
(A)
When a quick result is needed.
12
Which of the following are reasons for the use of estimation?
Answer
A
B
D
13
Which of the following should be considered when performing calculations?
Answer
A
C
14
When should you consider using estimation?
Answer
(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?
Answer
(B)
Round each item to $4 and multiply.
16
What would you do with the number 17.63 when rounding to 2 decimal places?
Answer
(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?
Answer
(D)
1.234 meters
18
When dealing with significant figures, what is the purpose?
Answer
(C)
To indicate the accuracy of the number.
19
Why are zeros used in a number when finding significant figures?
Answer
(B)
To maintain place value
20
What is the main focus of the topic of Estimation?
Answer
B
C
21
Which are important aspects of a correct calculation?
Answer
B
C
D
22
In estimation, why do we round the values before performing calculations?
Answer
(A)
To make the calculation easier.
23
Which is an example of when it would be suitable to estimate?
Answer
(C)
Estimating the cost of groceries
24
What does the accuracy depend on in an estimation?
Answer
(A)
The original values.
25
What do we call the numbers that contribute to the precision of a measurement?
Answer
(C)
Significant figures
26
Why is estimation a good tool to use?
Answer
(B)
To simplify complicated math problems
27
What rule needs to be followed when rounding to significant figures?
Answer
(C)
Look at the digit to the right.
28
What is the primary goal of estimation?
Answer
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?
Answer
(C)
2.8 m²
30
What is the main purpose of estimation?
Answer
(A)
To give a quick answer.
31
Which of the following are reasons to round values?
Answer
A
C
32
Which of the following could be classified under “Estimation”? (Select all that apply)
Answer
A
B
D
33
How is estimating often useful?
Answer
(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?
Answer
(A)
4
35
How can estimating help in everyday life?
Answer
(B)
Help budget spending.
36
Which one of these scenarios would need estimation?
Answer
(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?
Answer
(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?
Answer
(C)
The tree's height is relative to the building.
39
When rounding 0.00487 to 2 significant figures, what is the result?
Answer
(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...
Answer
(C)
Greater than or equal to 5
41
If asked to round 36.78 to 2 significant figures, what would be the answer?
Answer
(C)
37
42
In the number 0.0509, which digit is the first significant figure?
Answer
(B)
5
43
What are the main things that have to be considered when working to a sensible degree of accuracy?
Answer
A
C
D
44
When estimating, why might it be important to consider the context of the problem?
Answer
(A)
To determine the appropriate level of accuracy.
45
In estimation, what does 'significant figures' primarily tell you?
Answer
(B)
How accurate a number is.
46
What is the purpose of using significant figures?
Answer
(C)
To reflect the precision of a measurement.
47
In what situation is estimation more useful than an exact calculation?
Answer
(A)
When the calculation is complex.
48
What is the first step when estimating a solution?
Answer
(C)
Round values
49
If you are estimating the height of a tree next to a building, which strategy is most helpful?
Answer
(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?
