52+15{#blank#}1{#/blank#}15+52            6+2×6{#blank#}2{#/blank#}(6+2)×6

23-3×9{#blank#}3{#/blank#}27-9-9        50-14-16{#blank#}4{#/blank#}50-(14+16)

5×8{#blank#}1{#/blank#}5×7+5               4×4{#blank#}2{#/blank#}15                23+5{#blank#}3{#/blank#}7×5

1米{#blank#}4{#/blank#}90厘米              26厘米{#blank#}5{#/blank#}62厘米         100厘米{#blank#}6{#/blank#}2米

42-36+85{#blank#}7{#/blank#}69+（30-9）    63-（22-11）{#blank#}8{#/blank#}43+33    54-27{#blank#}9{#/blank#}45+8

26+8×12               (64-28)÷3                 274+ (491-137)