Superb primary Additions Activity "What are the two numbers give .........When they add."

 "What are the two numbers give .........When they add."

                                           " Which numbers do give answer 20 when they add?"  When I asked this question to my children they didn't give answer even tough they knew the additions. Later I came to know I must teach additions in a different way. Later I got an idea and prepared a wooden tray and bought Marbles.
                 Now I gave 10, 15, 9, 20..etc different count of marbles to my students and instructed them to place those marbles in two boxes of that tray as you like. Suppose one child placed or distributed his 15 marbles in two boxes like 9 and 6. Now I instructed my children to write those count of marbles on their slates like 9+6=15. Later I asked my children to shift one marble from one box and place that in other box. Now write the count of the marbles in two boxes. Then answer was 8+7=15.  I asked my children to continue like this and they wrote,
                                              7+8=15
                                              6+9=15
                                              5+10=15
                                             4+11=15
                                              3+12=15......like that.
                  Later I asked my children to explain and say few patterns without noticing of slate.