Monday, 1 October 2018

N1 Number Notation, Place Value

NUMBERS

 – why do we need to know them well

Numbers are usually written using: 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9. 


(1) To count: 1, 2, 3 strawberries    

Number Notation



PLACE VALUES

Value is the positional value of the digit in the number or where the digit is in the number. 

Stands for is another term used to describe ‘value’ in math.

What is a digit?

Digits are symbols or characters to represent a number in writing. 

Method to find the Value in a number

Step1: Underline the digit in the number given

Step2: Replace the numbers after the digit with zeros

Step3: Write the answer in numeric form

Example:

What is the value of the digit 4 in 854013?

Step1: Underline 4                                             854 013

Step2: Replace number to right of 4 to 0            4000

  Step3: Write : Answer: 4000

Practice:

What is the value of digit 3 in 

           (a) 89300,          (b) 55293,         (c) 30984


     ~~~~ END ~~~~ :)

N2 Number-Word-Number Conversion

Expressing Numbers in Words
(1) Numbers can be expressed in words using hundreds, thousands and millions.
(2) The last number to be written must be preceded by an ‘and’.
Example       
                        8 is two hundred and seventy-eight
 0 8 is five thousand six hundred and eight
70 is forty-five thousand six hundred and seventy


Method 1 – Grouping 

Example: Write 8765432 in words

Step 1: Separate numbers from right to left, 3 numbers in one group

Step2: Fill From left to right:

-         first underline is for hundred,
-         second underline is for thousand
-         third underline is for million
Step3: Write the word

Method 2: Place-Value-Table 

A place-value table can be drawn to teach placement of values and word notations. 


There are 4 main blocks to the place-value table:

(1) millions

(2) thousands

(3) hundreds and 

(4) decimals.


Within each block, it is further divided into hundreds, tens and ones. 

A given number is to be written onto the place value table from the right to left. 

Example: 

Write 930527 in words

Step1: Draw/Fill ‘9’,’3’,’0’,’5’,’3’,’7’ from the right to the left. 

Step2: READ the number from left to right, and including the word at every end of 

Method 3 : Writing 'Place Value Table' Title

Method 3 : Writing 'Place Value Table - PVT' Title

h t o (M)    h t o (T)      h t o

                     ^                ^       ^ ^ ^

  (millions  thousands  hundreds tens ones)


Example

Write 1459 in words


h t o (M)    h t o (T)      h t o          
       1      4 5  9                            Step 1: Write and fill in number                    
One thousand four hundred and fifty-nine    Step 2 : Write from left to right

Example: Write 1498012 in words
h t o (M)    h t o (T)      h t o            
      1          4 9 8          0 1 2                       Step 1: Write and fill in number   

Step 2: Write from left to right
  One million four hundred nine eight thousand and twelve  

Practice: 
Write the following in words : (a) 2930     (b) 47084     (c) 106507
{Ensure that the spellings are correct}

FROM WORDS TO NUMBER
METHOD1 (PVT)

Convert eight million seven hundred and sixty-five thousand four hundred and thirty-two to numbers

Step1: Underline hundred, thousand and million and write PVT in line with words 

            h t o (M)                                               h t o (T)             h t o

           eight million seven hundred and sixty-five thousand four hundred and thirty-two


Step 2: Convert words to number Fill in numbers from right to left

            h t o (M)                                               h t o (T)             h t o

         eight million seven hundred and sixty-five thousand four hundred and thirty-two

                8 (3rd)                                            765 (2nd )          432 (1st to convert)

Step 3: Answer : 8,765,432


METHOD2
Example           
Write Eight million, seven hundred and sixty-five thousand, four hundred and      thirty-two in number form.
 Step 1: Underline keywords – “Million’ (if any), ‘thousand’ 


 Step 2: Circle words before keywords ‘Million’, ‘thousand’ and the last group.
      8           ,                                 765                              ,                         432
Step 3Write numbers below the circle, and put a comma for the underline words. 

Answer: 8,765,432


                 ~~~~ END ~~~~ :)

N3. Whole Numbers : Comparing and Ordering Numbers (more than/less than)

MORE THAN

 
       OOOO△△△

                    4 is more than 3
The number of circles is MORE THAN the number of triangles

LESS THAN
              OOOO△△△
                     3 is less than 4
The number of triangles is LESS THAN the number of circles


SMALLEST, LARGEST 
Smallest: of the least value as compared to others
Largest: of the biggest value as compared to others
Example: 
            (a)    0 ,1 4, 7, 8
            (b)    2, 4, 6, 8, 0
            (c)    9, 8, 6, 4, 0
            (d)    3, 5, 4, 6, 9
Which number-set is arranged in order, beginning with the smallest number? (a)
Which number-set is arranged in order, beginning with the largest number? (c)

ODD NUMBER
Numbers ending with 1, 3, 5, 7, 9
Example
       19   ,    23,     835,    47,    1259,     361
EVEN NUMBER
Numbers ending with 0, 2, 4, 6, 8

ORDERING
Example
Arrange the following in decreasing order (big to small)
            23 642,          22 893,          25147
Method
Step1: Arrange numbers in rows
                        2 2  6 4 2
                        2 3  6 9 3
                        2 5 1 4 7
Step 2: Compare from left to right, until the column with different values, label from big (1) to small 
                        2 3  6 4 2   (2)
                        2 2  8 9 3   (3)
                        2 5  1 4 7   (1)
              same ↑    go next right number
                          ↑  5 is the largest number(1), then 3(2) , 2(1) <- label (1), (2) ,(3)
Step3: Write the answer with label (1), (2), (3) 
                      25147, 23693, 22642
Example
Arrange the following in increasing order (small to big)
            43642,          43193,          54147
Method
Step1: Arrange numbers in rows
                        4 3  6 4 2
                        4 3  1 9 3
                        5 4  1 4 7
Step 2: Compare from left to right, until the column with different values, label 3 (for 3 numbers comparison) for the largest number, and continue to next column
                        4 3  6 4 2   2
                        4 3  1 9 3   1
                        5 4  1 4 7   3             
                       ^           5 is biggest, strike, label 3(3 numbers), go next right number
                           ^       both are 3, go next right number
                                ^  6 and 1, label 2 for the bigger number, and 1 for the smaller number
Step3: Write the answer - label 1, 2, 3
                        43193, 43642, 54147

Solving 'More than' and 'Less than' questions
More than question (big - small)
Method
=> Big number - small number
Example: 102 is ______ more than 77.
Step1Circle/Underline 102, 77, More than (-)  => [big - small]
Step2: Write in equal form 
     => 102 -  77  ___    [Arrange  big number - small number = _____ ]
           102 - 77 = 25    
Step3: Solve 
        102 is 25 more than 77.

Example: 523 is 100 more than ____
Step 1Circle/Underline 523, 100, More than  => [big - small]
Step 2 Write in equal form
       => 523 - 100 = ____  [Arrange  big number - small number = _____ ]
             523 - 100 = 423  
Step 3 : Solve
              523 is 100 more than 423

Less than questions
(1) The first number is smaller than the second number
First number is smaller than the second number, big number subtract(-) the small number  
            First number smaller :  big number - small number 
Example
    68 is ______ less than 89.
Step1Circle/Underline 68(1st), 89(2nd) , Less than => 1st number(68) is smaller (-)
Step 2: Write in equal form (big number - small number)
           89 - 68 =  _____
       => 89 - 68 = 21
Step 3: Solve
              68 is 21 less than 89

(2) The first number is bigger than the second number
If the first number is bigger than the second number, ADD + both numbers
      First number bigger :  big number + small number 
Example: 523 is 100 less than ____
Step 1Circle/Underline 523(1st), 100 (2nd), less than: 1st number bigger (+)
Step 2 : Write in equal form
             523 + 100 =  _____ (Add both numbers)
             523 + 100 = 623
Step 3 : Solve
              523 is 100 less than 623

Example (more than / Less than)
Eric has 5 yellow balls. Rahul has 3 blue stickers.
           

(a) How many more sticker does Eric have?
Step 1: Underline, (method - more than => - )
Step 2:  Write in equal form
              5 - 3 = 2
Step 3: Solve
Eric has 2 more stickers than Bala

(b) How many stickers must Rahul has to have the same number of sticker as Eric?
Step 1: Underline and method to use
      [Rahul has less sticker than Eric ]
       3 is ___ less than 5 [1st number is smaller, big - small
Step 2 : Write in equal form
5 - 3 =. 
5 - 3 = 2
Step 3 : Solve
       Rahul has 2 fewer than Eric

COMPARE and ORDER Terms
(1)   Great/greater/greatest; as great as, greater than
(2)   Small/smaller/smallest; as small as, smaller than
(3)   Many/More/Most; as many as, more than       
(4)   Little/Less/Least; as little as, less than
(5)   Few/Fewer/Fewest; as few as, fewer than
(6)   Long/Longer/Longest; as long as, longer than                     
(7)   Short/Shorter/Shortest; as short as, shorter than
(8)   Tall/Taller/Tallest, taller than, as tall as  
(9)   Heavy/Heavier/Heaviest; as heavy as, heavier than                               
(10) Light/Lighter/Lightest; as light as; lighter than
(11) Decreasing / Increasing

~~~~~~~ The End  ~~~~~~~:)