操场上原来有多少人跳绳？

{#blank#}1{#/blank#}  {#blank#}2{#/blank#}   {#blank#}3{#/blank#}  = {#blank#}4{#/blank#} ({#blank#}5{#/blank#})

64-6{#blank#}1{#/blank#}64-60+6                  75-72{#blank#}2{#/blank#}75-27+8

20+8+13{#blank#}3{#/blank#}20+(8+13)       96-70{#blank#}4{#/blank#}16+70

80-60=         50 +20=        85-80=      73 +20=

83-9=            47+8=          56-34 =       23+55=

3×7=             49÷7=        4×8=         32÷4=

5×9=              18÷9=         6×4 =        12÷2=

8×7+8=            3×7+26=       6×7-25 =     48÷8+45=