Example 2

           549 078  +  286 949  +  54 832  =  --------                                Add using pairs of 10.

                                                                                                               First, add the ones,

                                                                                                               then add the tens.

                                 121 11
                                 549 078                    
                                 286 949
                     +            54 832
                    ----------------------
                                 890 859
                     ----------------------

                                8  +  9  +  2  =  8  +  2  +  9
                                                     =  10  +  9
                                                     =  19

                         1  +  7  +  4  +  3  =  7  +  3  +  4  +  1
                                                      =  10  +  5
                                                      =  15

Then, proceed with hundreds, thousands, ten thousands and hundred thousands.

                                   549 078  +  286 949  +  54 832  =  890 859 

Let's practise

1.  253 024  +  41 253  +  2 701  =

2.  463 015  +  235 184  +  8 428  =

3.  323 064  +  42 635  +  353 655  =

Example 3


                289 205  +  364 628  +  8 565  +  3 860  =


                                  122 11
                                  289 205
                                  364 628
                                      8 565
                         +           3 860
                        _______________
                                  666 258
                        _______________

Add using doubles.

Start from the ones and move towards the bigger place value. 

                                            5  +  8  +  5  =  5  +  5  +  8

                                                                = 10  +  8

                                                                = 18

                                   1  +  2  +  6  +  6  =  1  +  2  +  6  +  6

                                                                =  3  + 12 

                                                                = 15

                                   289 205  +  364 628  +  8 565  +  3 860  = 666 258

Let's Practise

1.  41 341  +  320 432  +  4 103  +  2 020  =

2.  342  956  + 298 614  +  195 495  +  6 547  =

3.  652 848  +  64 950  +  180 263  +  6 028  =