(ただし1と2を合せて12のような使い方は出来ません。)
42個の解法が見つかりました。
((2×2)×(5÷2))=10
((2×2)÷(2÷5))=10
((2×5)×(2÷2))=10
((2×5)+(2-2))=10
((2×5)-(2-2))=10
((2×5)÷(2÷2))=10
((2+(2×5))-2)=10
((2+2)×(5÷2))=10
((2+2)÷(2÷5))=10
((2-2)+(2×5))=10
((2÷2)×(2×5))=10
((5×(2×2))÷2)=10
((5×(2+2))÷2)=10
((5÷2)×(2×2))=10
((5÷2)×(2+2))=10
(2×((2×5)÷2))=10
(2×((2+5)-2))=10
(2×(2×(5÷2)))=10
(2×(2+(5-2)))=10
(2×(2-(2-5)))=10
(2×(2÷(2÷5)))=10
(2×(5×(2÷2)))=10
(2×(5+(2-2)))=10
(2×(5-(2-2)))=10
(2×(5÷(2÷2)))=10
(2+((2×5)-2))=10
(2-(2-(2×5)))=10
(2÷((2÷2)÷5))=10
(2÷((2÷5)÷2))=10
(2÷(2÷(2×5)))=10
(5×((2×2)-2))=10
(5×((2×2)÷2))=10
(5×((2+2)-2))=10
(5×((2+2)÷2))=10
(5×(2×(2÷2)))=10
(5×(2+(2-2)))=10
(5×(2-(2-2)))=10
(5×(2÷(2÷2)))=10
(5÷((2÷2)÷2))=10
(5÷(2÷(2×2)))=10
(5÷(2÷(2+2)))=10