4{#blank#}1{#/blank#}5=20     1{#blank#}2{#/blank#}1=1    18{#blank#}3{#/blank#}6=12    2{#blank#}4{#/blank#}3=6

6{#blank#}5{#/blank#}6=12     4{#blank#}6{#/blank#}4=16    3{#blank#}7{#/blank#}5=8     20{#blank#}8{#/blank#}10=10

A．＋   B．－   C．×

1×4={#blank#}1{#/blank#}×2

2×8={#blank#}2{#/blank#}×4

2×9={#blank#}2{#/blank#}×6

90-50+3890-50+38              9角1元                  4×32×6

2×42+2+2+2                        19分2角                  3+23×2