4{#blank#}1{#/blank#}5= 20          3{#blank#}2{#/blank#}5 = 8         19{#blank#}3{#/blank#}4 =3{#blank#}4{#/blank#}5

20{#blank#}5{#/blank#}10 = 10       2{#blank#}6{#/blank#}5＜10       5{#blank#}7{#/blank#}3＞12

5×5=                             3×2=                                  6×6=

2×2=                             4×5=                                  1×4=

7×3=                            4×7=                                  4×4=

28÷4=                           35÷5=                                42÷7=

56÷8=                           36÷9=                                21÷3=

口诀：