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IB Mathematics 
Approximation and Estimation
Approximation and Estimation 
Estimation: 
Estimation is an Intelligent guess made about something base on some 
information. Approximation is guess that is nearly exact. Estimate in science help 
scientist to guess before doing actual investigation. Estimate gives an idea about 
some quantities off hand before proper findings or measurement. For example, if 
you were asked to pay electricity bill given that you consumed 12units and the 
cost of a unit being 64frs. The cost of 12 units is 768frs 770. Why would 
SONEL Company prefer to approximate this value t0 770frs?. What if the value 
was 764? Will they still approximate it to 770 or 775. Its better to be roughly right 
than precisely wrong(Allan Greenspan, U.S. Federal Reserve Chairman -retired) 
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Introduction 
Activity: 
1. Guess intelligently the length and width of the classroom and 
calculate its area 
2. Estimate the amount of water you drink on daily basis. (1.5litres 
per day) 
3. Guess the weight of your exercise book (250g) 
4. Approximate the height and weight (mass) of your mate (1.7m, 
60kg or 500N) 
5. Estimate the weight of a football (396 to 463g) 
6. Estimate the angle between the wall the floor
Post Mathematics for Mathematics HL and SL 
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Review: Operations with Fractions and Decimals 
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Activity 1: Answers 
) 
3 
4 
) 
Remark: To divide a decimal 
by a power of 10n, move n-places 
to the left. To multiply a 
decimal number by a power of 
10n, move n-places to the right. 
Examples: 
a) 450歎 1000 
b) 780  1000 
Activity 1: Simplify as much as 
possible (Hint: Use BODMAS) 
) 
1 
2 
 2 
1 
2 
 1 
1 
6 
歎 2 
1 
3 
) 7 
1 
2 
 2 
1 
7 
 1 
2 
5 
+ 7 歎 3 
3) 
4 
3 
(2 
1 
2 
)  1 
1 
6 
歎 2 
1 
3 
4) 1.2 
0.012 
5) 9.02  100 
6) 2 歎 100 
7) 9.8+1.07+69 
8) 5-4.667 
9) 44.36 x 32 
10) a) 
0.3 
0.2 
b) 
0.3 
1000 
b) 
2 
100 
11) 0.2 x 1000
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Approximation and Estimation 
NB: Some numbers are too big 
to be rounded up or too small 
to be rounded down. 
To round up or down a decimal 
number (number with decimal 
point), We study the number of 
decimal places and we 
approximate accordingly. 
Examples: 
1) Round 2475 to the nearest 
10frs. 
(Ans: 2480frs ) 
2) Put 2.963 to 1decimal place 
(Ans: 3.1) 
3)Round 344frs to the nearest 
5frs. 
Rounding Up and Down: 
To round up and down a 
number or decimal, 
 Draw a vertical line (stroke) 
in front of the desired digit or 
unit 
 If the digit after the line is  
5 , round it up to one and 
add to the digit immediately 
before the line; the rest of 
the digits are considered 
zeros 
 If the digit after the line is 
<5, round it down so that the 
digits before the line remain 
unchanged and those after 
the line are assumed zeros
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Approximation and Estimation 
Remark: The value of any digit depends on its position. The value of 2 in 
the number 1267 is 100 and in 0.324 is 100th or 2dp. Given 2768.043, 
what is the value of each digit? 
The value of 2=thousand, 3=hundred, 6=ten, 8=unit, .0=tenth (1dp), 
4=hundredth (2dp), 3=thousandth (3dp) 
1000 
100 
10 
Unit 10th 
(thousand) 
(hundred) 
(ten) 
(tenth or 
1dp) 
100th 
(hundredth 
or 2dp) 
1000th 
(thousandth 
or 3dp) 
(1000) Or 103 100 or 102 10 or 
101 
1 or 
100 
0.1 or 10- 
1 
0.01 or 10-2 0.001 or 10-3 
Example: Copy and complete the table below 
Number 1dp 2dp Whole 
number 
or unit 
Neare 
st 
10frs 
Nearest 
100th 
Nearest 
Degree 
444.525 
5059.996 
267.537
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Approximation and Estimation 
Answer: Check for correctness 
Number 1dp 2dp Whole 
number 
or unit 
Neare 
st 
10frs 
Nearest 
100th 
Nearest 
Degree 
444.525 444.5 444.53 445 450 444.53 4450 
5059.996 5060.0 5060.00 5060 5060 5060.00 50600 
267.537 267.5 267.54 268 270 268.54 2680 
Significant Figures 
In the number 4380, 4=first significant figure or digit, 3=second significant 
figure, 8=third significant figure. and 0 is not significant although 0 has a 
value. However, in 4308, 0 is significant. 
Remark: 
 0 between two whole numbers or digits is significant 
 0 at the beginning or end of a number is not significant 
 If the digit after the required significant figure >=5, round up and add to 
the previous digit
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Approximation and Estimation 
Examples: Write the following numbers to 2 significant 
a) 0403670= 
b) 0.052407= 
c) 34.08945= 
d) 040567 (to 3 s.f.) 
Number 1dp 2dp 1sf 2sf 3sf Nearest 
whole 
number 
42.546 
0.9974 
1.9995 
295.6891
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Approximation and Estimation 
Examples: Write the following numbers to 2 significant 
a) 0403670=40 
b) 0.052407=0.052 
c) 34.08945=34 
d) 040567=34.1 to 3 sf 
Number 1dp 2dp 1sf 2sf 3sf Nearest 
whole 
number 
42.546 42.5 42.55 4 40 43.547 43 
0.9974 1.0 1.00 1.0 1.00 0.997 1 
1.9995 2.0 2.00 2 2.0 2.00 2 
295.6891 295.7 295.69 3 30 296 296
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Introduction 
Activity: 
 Write the biggest amount of money you dream to ever 
have in a life time 
 Write a number that starts with 1 and then followed by 
30 zeros. Do not write it in any other form? 
 Write another number that starts with a decimal point, 
continues with 20 zeros and 2 at the end. 
 Comment on this number 
 What is the most convenient way of writing such a 
number with many figures? Write it down. 
 What is the name given to this format of writing this 
number
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Standard Form 
Mathematicians or scientist use a convenient and economical manner 
or way to express very small numbers or very large numbers called 
the Standard Form. This form was adopted and made standard to be 
used all over the world. 
a  壱″    < ,  
a 10+  .  m ″ ≠  
a 10  .  m ″ ≠  
Examples: Express the following 
numbers in standard form 
1. 4500000 
2. 0.0000045 
3. 20 
4. 5 
5. 405 000 000 
Activity 1: Express the following 
numbers in standard form 
1. 10 
2. 0.000104 
3. 450000000000.0 
4. 0.01 
5. 9
Multiplication and Division of Numbers in Standard Form 
To multiply (or divide) numbers in standard form, multiply (or divide) 
the numbers (as) separately as well as the powers of 10 (102) 
(  10)( b 10) = (a  b)(10  10) 
テ10 
 
10 
= 
 
テ10 
10 
Examples: Evaluate 
1. (2  105 )(4  103) 
2. 3.6105 
1.2101 
3. (2  103)5 
4. Convert to decimals: 
a) 2.5 x 10-2 
b) 3.40 x 10-3 
c) 0.4 x 104 
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Activity 1: Simplify: 
1. (4  102)( 20 108) 
2. (3  103) 歎 ( 30 1010) 
3. 4103 
2.5104 
4. (7  105) 歎 ( 1.4 108) 
5. 5104 
2100 
6. (3  100)  ( 4.004 103) 
7. 4  ( 25  1012) 
8. 4104 2 
2.5102 3
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Review Exercise 
1. Write the number 
1 
400 
in a) Standard form b) two significant figures 
2. Simplify 3 
1 
3 
 2 
1 
4 
歎4 
1 
2 
+ 1 
1 
6 
3. Evaluate 
12.78103 
9  101 Express your answer in 
a) in standard form 
b) correct to 2 significant figures 
c) correct to 3 decimal places
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END

More Related Content

Estimation, Approximation and Standard form

  • 1. 息 Nsom Promise. All rights reserved. IB Mathematics Approximation and Estimation
  • 2. Approximation and Estimation Estimation: Estimation is an Intelligent guess made about something base on some information. Approximation is guess that is nearly exact. Estimate in science help scientist to guess before doing actual investigation. Estimate gives an idea about some quantities off hand before proper findings or measurement. For example, if you were asked to pay electricity bill given that you consumed 12units and the cost of a unit being 64frs. The cost of 12 units is 768frs 770. Why would SONEL Company prefer to approximate this value t0 770frs?. What if the value was 764? Will they still approximate it to 770 or 775. Its better to be roughly right than precisely wrong(Allan Greenspan, U.S. Federal Reserve Chairman -retired) 息 Nsom Promise. All rights reserved. Introduction Activity: 1. Guess intelligently the length and width of the classroom and calculate its area 2. Estimate the amount of water you drink on daily basis. (1.5litres per day) 3. Guess the weight of your exercise book (250g) 4. Approximate the height and weight (mass) of your mate (1.7m, 60kg or 500N) 5. Estimate the weight of a football (396 to 463g) 6. Estimate the angle between the wall the floor
  • 3. Post Mathematics for Mathematics HL and SL 息 Nsom Promise. All rights reserved.
  • 4. Review: Operations with Fractions and Decimals 息 Nsom Promise. All rights reserved. Activity 1: Answers ) 3 4 ) Remark: To divide a decimal by a power of 10n, move n-places to the left. To multiply a decimal number by a power of 10n, move n-places to the right. Examples: a) 450歎 1000 b) 780 1000 Activity 1: Simplify as much as possible (Hint: Use BODMAS) ) 1 2 2 1 2 1 1 6 歎 2 1 3 ) 7 1 2 2 1 7 1 2 5 + 7 歎 3 3) 4 3 (2 1 2 ) 1 1 6 歎 2 1 3 4) 1.2 0.012 5) 9.02 100 6) 2 歎 100 7) 9.8+1.07+69 8) 5-4.667 9) 44.36 x 32 10) a) 0.3 0.2 b) 0.3 1000 b) 2 100 11) 0.2 x 1000
  • 5. 息 Nsom Promise. All rights reserved. Approximation and Estimation NB: Some numbers are too big to be rounded up or too small to be rounded down. To round up or down a decimal number (number with decimal point), We study the number of decimal places and we approximate accordingly. Examples: 1) Round 2475 to the nearest 10frs. (Ans: 2480frs ) 2) Put 2.963 to 1decimal place (Ans: 3.1) 3)Round 344frs to the nearest 5frs. Rounding Up and Down: To round up and down a number or decimal, Draw a vertical line (stroke) in front of the desired digit or unit If the digit after the line is 5 , round it up to one and add to the digit immediately before the line; the rest of the digits are considered zeros If the digit after the line is <5, round it down so that the digits before the line remain unchanged and those after the line are assumed zeros
  • 6. 息 Nsom Promise. All rights reserved. Approximation and Estimation Remark: The value of any digit depends on its position. The value of 2 in the number 1267 is 100 and in 0.324 is 100th or 2dp. Given 2768.043, what is the value of each digit? The value of 2=thousand, 3=hundred, 6=ten, 8=unit, .0=tenth (1dp), 4=hundredth (2dp), 3=thousandth (3dp) 1000 100 10 Unit 10th (thousand) (hundred) (ten) (tenth or 1dp) 100th (hundredth or 2dp) 1000th (thousandth or 3dp) (1000) Or 103 100 or 102 10 or 101 1 or 100 0.1 or 10- 1 0.01 or 10-2 0.001 or 10-3 Example: Copy and complete the table below Number 1dp 2dp Whole number or unit Neare st 10frs Nearest 100th Nearest Degree 444.525 5059.996 267.537
  • 7. 息 Nsom Promise. All rights reserved. Approximation and Estimation Answer: Check for correctness Number 1dp 2dp Whole number or unit Neare st 10frs Nearest 100th Nearest Degree 444.525 444.5 444.53 445 450 444.53 4450 5059.996 5060.0 5060.00 5060 5060 5060.00 50600 267.537 267.5 267.54 268 270 268.54 2680 Significant Figures In the number 4380, 4=first significant figure or digit, 3=second significant figure, 8=third significant figure. and 0 is not significant although 0 has a value. However, in 4308, 0 is significant. Remark: 0 between two whole numbers or digits is significant 0 at the beginning or end of a number is not significant If the digit after the required significant figure >=5, round up and add to the previous digit
  • 8. 息 Nsom Promise. All rights reserved. Approximation and Estimation Examples: Write the following numbers to 2 significant a) 0403670= b) 0.052407= c) 34.08945= d) 040567 (to 3 s.f.) Number 1dp 2dp 1sf 2sf 3sf Nearest whole number 42.546 0.9974 1.9995 295.6891
  • 9. 息 Nsom Promise. All rights reserved. Approximation and Estimation Examples: Write the following numbers to 2 significant a) 0403670=40 b) 0.052407=0.052 c) 34.08945=34 d) 040567=34.1 to 3 sf Number 1dp 2dp 1sf 2sf 3sf Nearest whole number 42.546 42.5 42.55 4 40 43.547 43 0.9974 1.0 1.00 1.0 1.00 0.997 1 1.9995 2.0 2.00 2 2.0 2.00 2 295.6891 295.7 295.69 3 30 296 296
  • 10. 息 Nsom Promise. All rights reserved. Introduction Activity: Write the biggest amount of money you dream to ever have in a life time Write a number that starts with 1 and then followed by 30 zeros. Do not write it in any other form? Write another number that starts with a decimal point, continues with 20 zeros and 2 at the end. Comment on this number What is the most convenient way of writing such a number with many figures? Write it down. What is the name given to this format of writing this number
  • 11. 息 Nsom Promise. All rights reserved. Standard Form Mathematicians or scientist use a convenient and economical manner or way to express very small numbers or very large numbers called the Standard Form. This form was adopted and made standard to be used all over the world. a 壱″ < , a 10+ . m ″ ≠ a 10 . m ″ ≠ Examples: Express the following numbers in standard form 1. 4500000 2. 0.0000045 3. 20 4. 5 5. 405 000 000 Activity 1: Express the following numbers in standard form 1. 10 2. 0.000104 3. 450000000000.0 4. 0.01 5. 9
  • 12. Multiplication and Division of Numbers in Standard Form To multiply (or divide) numbers in standard form, multiply (or divide) the numbers (as) separately as well as the powers of 10 (102) ( 10)( b 10) = (a b)(10 10) テ10 10 = テ10 10 Examples: Evaluate 1. (2 105 )(4 103) 2. 3.6105 1.2101 3. (2 103)5 4. Convert to decimals: a) 2.5 x 10-2 b) 3.40 x 10-3 c) 0.4 x 104 息 Nsom Promise. All rights reserved. Activity 1: Simplify: 1. (4 102)( 20 108) 2. (3 103) 歎 ( 30 1010) 3. 4103 2.5104 4. (7 105) 歎 ( 1.4 108) 5. 5104 2100 6. (3 100) ( 4.004 103) 7. 4 ( 25 1012) 8. 4104 2 2.5102 3
  • 13. 息 Nsom Promise. All rights reserved. Review Exercise 1. Write the number 1 400 in a) Standard form b) two significant figures 2. Simplify 3 1 3 2 1 4 歎4 1 2 + 1 1 6 3. Evaluate 12.78103 9 101 Express your answer in a) in standard form b) correct to 2 significant figures c) correct to 3 decimal places
  • 14. 息 Nsom Promise. All rights reserved. END

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