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    E:\Working\Orange_Education\Math_Genius_2\Open_Files\Chap_04
                   \ 06-Oct-2025  Bharat Arora   Proof-10                                   Reader’s Sign _______________________ Date __________

                  Regrouping Hundreds and Tens

                  Sometimes we need to regroup at more than one place while doing subtraction.

                  Let us understand this with the help of an example.

                  Example 3: Subtract 253 from 800.

                  Solution:  Step 1. Write the smaller number below the bigger                               H    T    O
                                  number in columns and start subtracting from the ones                      8    0    0

                                  place.                                                                 –   2    5    3

                                  Since there are no ones, regroup the tens and ones.

                                    But there are no tens.
                                  So, first regroup the hundreds and tens and then the tens and ones.

                                  8 hundreds + 0 tens = 7 hundreds + 10 tens

                                  and 10 tens + 0 ones = 9 tens + 10 ones

                   Step 2.  Subtract the ones. Step 3.  Subtract the                  Step 4.  Subtract the

                              10 – 3 = 7 ones                    tens.                           hundreds.
                                  H     T   O                    9 – 5 = 4 tens                  7 – 2 = 5 hundreds
                                        9                            H    T    O                      H    T   O

                                   7   10 10                              9                                9
                                   8    0    0                       7    10 10                       7   10 10
                               –   2    5    3                       8    0    0                      8    0    0

                                             7                   –   2    5    3                  –   2    5    3
                                                                          4    7                      5    4    7

                             Thus, 800 – 253 = 547.

                   Shortcut Method                                     In order to subtract numbers like 9, 99, etc.

                                                                       from  any  number,  we  first  subtract  10,  100,
                   When the last digits of the minuend                 etc.  from  the  number,  since  that  is  easier.
                   are zeros, subtract 1 from both the                 Then, we add 1 to this difference to get the

                   numbers. It makes the subtraction                   answer. E.g. 46 – 9 = 46 – 10 + 1 = 37.

                   easier.                                             Similarly, 465 – 99 = 465 – 100 + 1 = 366

                       H    T    O                    H     T   O      As we have subtracted 100, which is 1

                       8    0    0        –1           7    9    9     more than 99, we add 1 to 365 to get the
                   –   2    5    3        –1       –   2    5    2     answer.
                                                       5    4    7     Now, find 730 – 9 and 730 – 99.

                  80                                                                                    Mathematics-2

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