Page 1 - Lesson Note
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SAI International School


                                            Class :  VI

        Mathematics


        Chapter-2- Whole Numbers


        Lesson Note: 3


        Subtopics:
                     Identity for addition and multiplication
                     Application of Distributive property
                     Pattern

              Identity for addition and multiplication:
                            Additive identity
               Any whole number remains unchanged when added to zero.
                For any whole number zero is the additive identity.
                            Multiplicative identity
               Any whole number remains unchanged when multiplied by one.
                For any whole number one is the multiplicative identity.
              Application of Distributive property
                            To make some multiplication easier.
                              Case I: Find the value of the following:  54279 × 92 + 8 × 54279
                                                                         = 54279 × (92 + 8)
                                                                         = 54279 × 100
                                                                         = 5427900

                              Case II: Find the product:                        85456 × 1001
                                                                         = 85456 × (1000 + 1)
                                                                         = 85456 × 1000 + 85456 × 1
                                                                         = 85456000 + 85456
                                                                         = 85541456



                            To solve some real life cases given in the form of word sums.

                            Case III:

                              Eg.1)  A taxi driver filled his car petrol tank with 40 liters of petrol on Monday.
                              The next day, he filled the tank with 50 liters of petrol. If the petrol costs Rs.44
                              per liter, how much did he spend in all on petrol?

                                     Answer:
                                                   The cost of one liter petrol = Rs.44


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