Using place value strategy find the sum of 357+164

Well first you need to set it up ike this
                                 357  
                                        + 
                                 164

Now add 7+4= 11 but we still have to carry the one to the 5. So now the 5 is a 6. Put the one at the bottom .
                                               367
                                                    +
                                               164

Now 6+6 is 12 so carry the 1 to the 3 and the three is now a 4. But the the 2 in the 10s collum.
 
                                             467
                                                  +
                                             164

Easy PART! 1 + 4= 5 but the 5 in the 100s collum and your answer is

521! Hope this helped. Sorry if it didnt
 

                                              

You didn’t put the necessary image to solve the question : p

No solution : there is no number of boxes that she bought