Mathematics for IGCSE & O level - Estimation (Section 3)
1
What is 3.1 x 1.9 (correct to 1 s.f.)?
2
What is the approximate value for 52417 rounded to 2 significant figures?
3
When estimating the area of a rectangle, the length is 17.1cm and the width is 6.3 cm. What is the estimated area?
4
When you have to round to the nearest 2 d.p., what are the digits you need to consider?
5
What is a common mistake when rounding to a given number of significant figures?
отговор(C)
Counting the wrong number of zeros.
6
What is the first step in estimating the cost of 24 golf balls at $5.75 each?
отговор(B)
Round $5.75 to one significant figure.
7
If the digit to the right of the desired place to round to is less than 5, how do you round?
8
What is the answer for 99/4.6 to 1 significant figure?
9
What is 1.5736 rounded to 2 decimal places?
10
When can you use estimation?
11
What is 3.520 to 1 decimal place?
12
What does 'd.p.' stand for?
13
How many significant figures does the number 100 have?
14
How should you express your answer when you have rounded numbers in a calculation?
отговор(D)
State the accuracy of your answer when you have rounded them.
15
Which of the following are important when estimating answers to problems?
16
What does it mean for a digit to be 'significant'?
отговор(C)
The digit contributes to the value of the number.
17
Which of the following statements is true about estimation?
отговор(B)
It involves simplifying a calculation to find an approximate answer.
18
Which of the following is NOT an example of estimation?
отговор(B)
Using a calculator to find an answer.
19
What is 17100 rounded to 1 s.f.?
20
What does it mean to 'estimate' an answer to a problem?
отговор(C)
To find an approximate answer using simpler calculations.
21
In which situation might estimation be the preferred method for a calculation?
отговор(B)
When you need a quick answer and precision is not critical.
22
When rounding 8.478 to 1 d.p., what is the result?
23
What should the approximation of the value 16.56 / 2.28 be?
24
What is the approximate value of 19.89 to 1 significant figure?
25
When are zeros significant?
26
What is the general method to estimate answers to problems?
отговор(A)
Round each number to one significant figure and perform the calculation.
27
What would be a suitable degree of accuracy for giving the value of a table’s length and width measurement?
отговор(B)
Round to the same accuracy as the original measurements.
28
отговор(C)
Zeros at the beginning of a decimal number.
29
Which number is used to maintain the place value of the digit when we want to round?
30
If a number is 3.874, which digit dictates what it rounds to when rounding to 2 significant figures?
31
What are the key points to remember about significant figures?
32
When rounding to a given number of decimal places, what should you look at?
отговор(B)
The digit immediately to the right of the desired decimal place.
33
What is the first non-zero digit in the number 0.0056?
34
When rounding numbers to estimate a square root, which of the following should you do?
отговор(C)
Round to the nearest perfect square.
35
What is an example of estimation?
отговор(B)
Rounding a number to one significant figure before performing a calculation.
36
In a calculation, if one of the values is accurate to 1 decimal place, to what degree of accuracy should you express the answer?
37
When rounding to 1 d.p., what do you look at?
отговор(A)
The second digit after the decimal point
38
When rounding to 1 s.f., how many digits are kept?
39
When you are rounding a number, which side are you using?
40
What is 126 rounded to 1 s.f.?
41
What is the most significant digit in the number 0.00456?
42
What is one reason to round numbers to one significant figure when estimating the answer to a problem?
отговор(A)
To make the calculation simpler.
43
What is 7.0666 rounded to 2 decimal places?
44
What is the approximate value for 0.71*sqrt(162)?
45
Which of the following is a good reason to use estimation?
отговор(A)
To get a quick approximate answer.
46
What are the steps to estimate the result of a calculation, rounding to 1 significant figure?
отговор(B)
Round each number to 1 significant figure, then perform the calculation.
47
What is the meaning of 1 s.f.?
49
What do you call the places to the right of the decimal point?
50
When rounding to a given number of decimal places, you look at the digit to the _?
