Saturday 21 January 2012

Different Patterns in Multiplication Facts

Hello friends,Previously we have discussed about 3 digit subtraction with regrouping and now we are back again with one more algebra 1 topic for grade III of icse board. Our today’s topic is very much interesting. Today we will learn Patterns in multiplication facts.
There are many students who put lots of efforts and time to memorize facts in earlier grades. And there are a few who can really recall them easily. When some multiplication questions are assigned to them there may be only 2 or 4 students who can solve all of them quickly with cent percent accuracy. Other still take time to solve them after putting so much efforts.
 Multiplication facts help you to memorize table and also make it easy to create any number’s table with little effort.
Multiplication facts are easiest to learn when we find some pattern or relating something with other we already know.(want to Learn more about Patterns in Multiplication ,click here)

First we start with what is multiplication. I know you all must be laughing! We all know what multiplication is.

Multiplication is simply a fast way to add group of equal size.

Example:
            5 x 3 =15
            (Number of groups) x (number of elements in each group) = total all together
One important thing is, the number of elements in each group must be same.

An important property of multiplication is Commutative property which states:
When we multiply two numbers their result is always same regardless of the order of the numbers.

Example:
            3x4 = 4x3 =12

“0” family facts:
            Any thing times “0” is 0.

            Examples:
                        0x1 = 0
                        0x2 = 0
                        6x0 =  0

“1” family facts:
          Any number times “1” is same number.
         
            Example:
                        1x4 = 4
                        5x1 = 5
                        9x1 = 1


“2” family facts:
          Any number times “2” is double the number.

            Example:
                        2x2 = 4
                        2x3 = 6
                        2x8 = 16
                        7x2 = 14

“4” family facts
          To multiply any number by 4 double it two times.
                     
            Example:
                        4x3 = 3x2x2 = 12
                        4x5 = 5x2x2 = 20
                        6x4 = 6x2x2 = 24


“5” family facts:
            To multiply any number with 5 we follow two steps.

            Step 1: Half the number we are multiplying.
                        Example: 5x3 = 1.5
                                        5x4 = 2
                                        5x5 = 2.5
                                        5x6 = 3
            Step 2: Again this step is further divided in two.

                        Step 2a: If number is even add zero.
                        Example:
                                        5x4 = 2 0
                                        5x6 = 3 0
                        Step 2b: If number is odd remove decimal.
                        Example:
                                        5x3 = 15
                                        5x5 = 25               

“6” family facts
                             For the even numbers only. That using this method we can only                                      multiply even numbers with “6”.

                                    Step 1: Half the number we are multiplying.
                                    Example:
                                                6x2=1
                                                6x4=2
                                                6x6=3

                                    Step 2: Put the number we are multiplying after the number(result                                                           of sep1)
                                    Example:
                                                6x2=12
                                                6x4=24
                                                6x6=36


                                             
“9” family facts
            To multiply any number with 9 follows two steps:
         
            Step 1:Half the number we are multiplying.
            Example:
                        9x3 = 2
                        9x4 = 3
                        9x6 = 5
            Step 2: Add a number with totals 9 with the first number.
            Example:
                        9x3 = 27 (2+7=9)
                        9x4 = 45 (4+5=9)
                        9x6 = 54 (5+4=9)

                                 
                     
“11” family facts
                   I will give you two methods to multiply numberswith“11”.
                     
                        Method 1: For single digit numbers.
                                         Number multiplied with 11 is just duplicated.
                                         Example:
                                                11x3=33
                                                11x5=55
                                 
                        Method 2: For two digit numbers.
·        Write the two digit number with space between them.  
                                                Example:
                                                            11x18=1_8
                                                            11x14=1_4
·        Add the both number and put result between the digits.
                                                 Example:
                                                            11x18=(1+8=9)=198
                                                            11x14=(1+4=5)=154

We have discussed some major patterns in multiplication facts. To get familiar with this will surely help you to complete your assignment and tests easily and in less time and if anyone want to know about Estimation in addition and subtraction then they can refer to internet and text books for understanding it more precisely.Read more maths topics of different grades such as Possible combinations in the next session here.

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