①99          ②990            ③ 89

 5×8=            6×7=             9×3=             2×8=

36÷9=            48÷6=            14÷2=            36÷6=

500+200=          800-400=          930-300=          450-150=

720+60=           960-600=          450+90=           860-80=

40÷7=            52÷8=            34÷6=            85÷9=

88÷4=          71-38=          71+39=          32÷8-3=

600×9=         5×800=         90÷3=           35-3×8=

{#blank#}1{#/blank#}+28=100      260-{#blank#}2{#/blank#}=200

{#blank#}3{#/blank#}-20=50        28×{#blank#}4{#/blank#}=560

960÷{#blank#}5{#/blank#}=30         {#blank#}6{#/blank#}÷28=20