168﹣52﹣48=                                       37+125+63+175=

①75+63=63+{#blank#}1{#/blank#}

②120+60={#blank#}2{#/blank#}+120

③123+862+257=123+257+{#blank#}3{#/blank#}

④90+a={#blank#}4{#/blank#}+90  

⑤a+b={#blank#}5{#/blank#}+a

⑥a+{#blank#}6{#/blank#}=26+{#blank#}7{#/blank#}

37＋16{#blank#}1{#/blank#}16＋37       42－19{#blank#}2{#/blank#}43－19      51＋19{#blank#}3{#/blank#}32＋28

4900÷25÷4   201×36-36  224+607+576+293

80+（146-46）×2   25×50×4×6  72×125

420÷35                       736＋137＋264＋363                       304－198