算一算。 40÷5= 64÷8= 5×9= 4×7= 6×4÷8= 42÷6

问题：

算一算。    

40÷5=                      64÷8=                           5×9=                        4×7=    

6×4÷8=                   42÷6=                           48÷8=                      64÷8×2=    

49÷7=                      3×6÷2=                        40÷5+5=                  81÷9=    

63÷9=                    （20+15）÷7=                 6×4÷3=                   5×6+7=