{#blank#}1{#/blank#}

①250﹣120＝

②540+180＝

③640﹣250＝

④720﹣170＝

⑤420+370＝

⑥320+370＝

600+90=               900-400=

750-700=               200+300=

60+200=                40+100=

280-200=               300+600=

570-70=                 460-200=

28+23{#blank#}1{#/blank#}64          72-28{#blank#}2{#/blank#}54          460+370{#blank#}3{#/blank#}240+590

62+28{#blank#}4{#/blank#}82+18      26+49{#blank#}5{#/blank#}92-17       15+120{#blank#}6{#/blank#}140-47