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

3 {#blank#}4{#/blank#} 0＝3     2 {#blank#}5{#/blank#} 1＝1     4 {#blank#}6{#/blank#} 1＝5

① {#blank#}1{#/blank#}；

② {#blank#}2{#/blank#}；

③ {#blank#}3{#/blank#}；

④ {#blank#}4{#/blank#}.

2+3=            2-2=            4-2=            2+0=

4-3=            3+2=            2+2=            5-2=

0+3=            5-3=            2-0=            3-2=

5-1=            3+1=            2-1=            2+1=