Page 32 - ArithBook5thEd ~ BCC
P. 32

order of operations, which we will say more about later.)


                   Let’s try another simple division problem.

               Example 25. Find the quotient and remainder of the division 162 ÷ 42.


               Solution. Putting the dividend and divisor into the long division form, wehave


                               42         16 2














               Let’s estimate the number of subtractions that we’ll need to perform. 40 goes into 160 four times, so,
               perhaps four is a good guess. But 4 × 42 = 168, which is too big (bigger than the dividend). So we
               lower our estimate by 1. We get 3 × 42 = 126, which is less than the dividend, so this must be the
               right choice.

                                             3
                               42         16 2
                                        −12 6











               Subtracting, we obtain the remainder

                                             3
                               42         16 2
                                        −12 6
                                            36










               which is less than the divisor, as it should be. Thus, the quotient is 3 and the remainder is 36. As a
               check, we verify that 3 × 42 + 36 = 162. (Multiplication before addition.)



                                                           Page 32
   27   28   29   30   31   32   33   34   35   36   37