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SAI International School

                                                        CLASS-VI
                                                      Mathematics
                                               CHAPTER 5 PRIME TIME
                                                    LESSON NOTES



                    SUBTOPIC: Divisibility Rules

                        Divisibility by 2: If the number ends with 2, 4, 6, 8 or 0, it is divisible by
                          2.
                               Ex:  28, 54, 96
                        Divisibility by 3: If the sum of the digits is a multiple of 3, then the
                          number is divisible by 3.
                              Ex- 219, Sum of the digits of the number is 2 + 1 + 9 = 12;    12 ÷ 3 = 4.
                          Therefore, 219 is divisible by 3.

                        Divisibility by 4: If the last 2 digits of any number are divisible by 4, then

                          that number is divisible by 4.
                          Ex: 1936;   Last 2 digits are 36 and 36 ÷ 4 = 9.
                          Therefore, 1936 is divisible by 4.

                        Divisibility by 5: If the digit in the ones place of a number is 5 or 0, then
                          it is divisible by 5.
                          Ex: 6205 ends in 5. Therefore, 6205 is divisible by 5.

                        Divisibility by 6: If a number is divisible by 2 and 3, then that number is
                          divisible by 6.
                           Ex: 246. It is divisible by 2 as it ends with 6. Now, 2 + 4 + 6 = 12. 12 is
                          divisible by 3, so 246 is divisible by 3 also.
                           This shows that 246 is divisible by 2 and 3. Therefore, 246 is divisible by
                           6.

                        Divisibility by 8: A number is divisible by 8 if the number formed by its
                          last three digits is divisible by 8.
                                Ex: 10216,   Last 3 digits are 216. 216 ÷ 8 = 27.
                          Therefore, 10216 is divisible by 8.

                        Divisibility by 9: A number is divisible by 9 if the sum of its digits is
                          divisible by 9.
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