①{#blank#}1{#/blank#}   ②{#blank#}2{#/blank#}   ③{#blank#}3{#/blank#}   ④{#blank#}4{#/blank#}    ⑤{#blank#}5{#/blank#}。

4×2＝8

15÷3={#blank#}1{#/blank#}   21÷5={#blank#}2{#/blank#}……{#blank#}3{#/blank#} 

28＋45={#blank#}4{#/blank#}  4×7={#blank#}5{#/blank#} 

300＋700={#blank#}6{#/blank#}   418＋200={#blank#}7{#/blank#} 

640－600={#blank#}8{#/blank#}   396－300={#blank#}9{#/blank#} 

320＋400={#blank#}10{#/blank#}   53－35={#blank#}11{#/blank#}

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=