Page 36 - Start Up Mathematics_3
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Th    H    T    O               Th    H     T    O              Th    H    T     O
                  (g)                             (h)                              (i)
                            1     4    3     2               2    0     0    6               3    5    4     2
                        +   5     0    2     6          +         8     5    2          +    6    2    1     3






              2.  Add the following numbers.
                  (a)  6214 + 2073        (b)  7876 + 2012        (c)  3461 + 2228        (d)  6291 + 6507


            Addition of Two 4-Digit Numbers                                   Quick Tip

            (with carry over)
                                                                               This method is also
            Example 2:       Add 8254 and 7918.                                called “Addition by
                                                                               regrouping.”
            Solution:             Th    H     T    O

                                   8    2     5    4          Step 1: Add the ones.

                                +  7    9     1    8                   4 + 8 = 12
                                                  1 2



                                 Th    H     T    O

                                  8    2   1 5    4           Step 2:  12 is a 2-digit number. Write 2 in the
                                                                       ones place and carry over 1 to the
                             +    7    9     1    8
                                                                       tens place. Add the tens including
                                             7    2                    the 1 carried over.

                                                                       1 + 5 + 1 = 7
                                 Th    H     T    O

                                  8    2   1 5    4           Step 3:  Add the hundreds (there is no carry

                             +    7    9     1    8                    over).
                                      1 1    7    2                    2 + 9 = 11



                                 TTh Th      H     T    O
                                       1 8    2   1 5   4     Step 4:  11 is a 2-digit number.  Write 1 in

                                                                       the hundreds place and carry over
                             +          7     9    1    8              1 to the thousands place. Add the
                                       1 6    1    7    2              thousands including the 1 carried

                                                                       over.
                                                                       1 + 8 + 7 = 16




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