N6 Numbers : Multiplication

MULTIPLY / TIMES / MULTIPLICATION / X

           

(1) Multiplication is repeated addition.

Example: 6 x 3

      3   +  3   +   3     +  3    +    3   +   3    =  18

            6 x 3 = 3 + 3 + 3 + 3 + 3 + 3

                     = 6 + 6 + 6

                     = 3 x 6 = 18

(2) Multiplication (times ) => total number of “groups of”

           

6 x 3 = total number of 6 “groups of” 3

                                or  3 “groups of” 6

(3) Multiplication can be shown as a rectangle

 (4)  Order of the numbers can be changed

            6 x 3

     =  3 x 6

     =  18

Doing Word Problems

Ani has 8 balls. Carol has 4 times as many balls as Ani. How many balls does Carol have?

Method

Step1: [Knowthe story and underline] Who and what? 

            Ani : 8 balls 

            Carol : 4 times  

Step2: [Plan]. What is Required: Carol’s balls (double underline)

            Ani x 4

Step3: [Do]

            8 x 4 - 32

Carol has 32 balls.

Example

There are 12 pupils in each IT class. There are 7 IT classes in total. How many pupils are in the IT classes?

Step1: [Knowthe story and underline] Who and what? 

            IT class :  12 pupils

            Total          :7 classes  

Step2: [Plan]. What is Required: Pupils in IT classes

            pupil in 1 IT class x 7

Step3: [Do]

            12 x 7

There are 84 pupils.

<<Learners must remember the 1 – 12 multiplication tables>> 

MULTIPLYING BY TENS HUNDREDS AND THOUSANDS

Whole numbers are multiply by 10s, 100s, 1000s:

When any whole number is multiply by 10, 100, or 1000, we can ‘ADD’ the corresponding 0s to the end of the number.

Example:

(a) 8365 x     10   = 83650       <ADD 0s to the numbers when multiply by 10s>

(b) 8635 x   100   = 836500     <ADD 00s to the numbers when multiply by 100s>

(c) 8635 x 1000   = 8635000   <ADD 000s to the numbers when multiply by 1000s>

WHOLE NUMBERS MULTIPLY by MULTIPLES of 10s, 100s, 1000s:

Method: Split the 10 multiples

Example:

a.    15 x 30 = 15 x 3 x 10   <Split into 10 multiples >

             = 45 x 10 = 450     

b.    15 x 300 = 15 x 3 x 100

               = 45 x 100 = 4500

c.     15 x 3000 = 15 x 3 x 1000

                 = 45 x 1000 = 45000

DECIMAL NUMBERS multiply by 10s, 100s, 1000s

When a decimal number is MULTIPLY by 10, the decimal value shifts by ONE PLACE to the RIGHT.

   

     1 “shift” of decimal point to the right is equal to multiply by 10.

Examples:

Practice

Find    (a) 1.5 x 3000     

           (b)   0.013 x 1000  

           (c)  2.08 x 10

MULTIPLCATION WORD NOTATION

 

Examples:

7 x 2 is             (a) product of 7 and 2

                        (b) 7 times 2

                        (c) Multiply 7 by 2

    

            ~~~~ END ~~~~ :)