（ただし１と２を合せて１２のような使い方は出来ません。）
51個の解法が見つかりました。
(((8+9)-5)-2)=10
((2×5)×(9-8))=10
((2×5)÷(9-8))=10
((5+9)-(8÷2))=10
((8+(9-2))-5)=10
((8+(9-5))-2)=10
((8+9)-(2+5))=10
((8-(2-9))-5)=10
((8-(5-9))-2)=10
((8-2)+(9-5))=10
((8-2)-(5-9))=10
((8-5)+(9-2))=10
((8-5)-(2-9))=10
((9+(8-2))-5)=10
((9+(8-5))-2)=10
((9-(2-8))-5)=10
((9-(5-8))-2)=10
((9-2)+(8-5))=10
((9-2)-(5-8))=10
((9-5)+(8-2))=10
((9-5)-(2-8))=10
((9-8)×(2×5))=10
(2×(5×(9-8)))=10
(2×(5÷(9-8)))=10
(2÷((9-8)÷5))=10
(5×(2×(9-8)))=10
(5×(2÷(9-8)))=10
(5+(9-(8÷2)))=10
(5-((8÷2)-9))=10
(5÷((9-8)÷2))=10
(8+((9-2)-5))=10
(8+((9-5)-2))=10
(8+((9-5)÷2))=10
(8+(9-(2+5)))=10
(8-((2+5)-9))=10
(8-((5-9)÷2))=10
(8-(2+(5-9)))=10
(8-(2-(9-5)))=10
(8-(5+(2-9)))=10
(8-(5-(9-2)))=10
(9+((8-2)-5))=10
(9+((8-5)-2))=10
(9+(5-(8÷2)))=10
(9+(8-(2+5)))=10
(9-((2+5)-8))=10
(9-((8÷2)-5))=10
(9-(2+(5-8)))=10
(9-(2-(8-5)))=10
(9-(5+(2-8)))=10
(9-(5-(8-2)))=10