（ただし１と２を合せて１２のような使い方は出来ません。）
40個の解法が見つかりました。
((2+5)+(9-6))=10
((2+5)-(6-9))=10
((2+9)+(5-6))=10
((2+9)-(6-5))=10
((2-6)+(5+9))=10
((5+(2+9))-6)=10
((5+(6+9))÷2)=10
((5+9)+(2-6))=10
((5+9)-(6-2))=10
((5-6)+(2+9))=10
((6+(5+9))÷2)=10
((9+(2+5))-6)=10
((9+(5+6))÷2)=10
((9-6)+(2+5))=10
(2+((5+9)-6))=10
(2+(5+(9-6)))=10
(2+(5-(6-9)))=10
(2+(9+(5-6)))=10
(2+(9-(6-5)))=10
(2-((6-5)-9))=10
(2-((6-9)-5))=10
(2-(6-(5+9)))=10
(5+((2+9)-6))=10
(5+(2+(9-6)))=10
(5+(2-(6-9)))=10
(5+(9+(2-6)))=10
(5+(9-(6-2)))=10
(5-((6-2)-9))=10
(5-((6-9)-2))=10
(5-(6-(2+9)))=10
(5÷(2-(9÷6)))=10
(9+((2+5)-6))=10
(9+(2+(5-6)))=10
(9+(2-(6-5)))=10
(9+(5+(2-6)))=10
(9+(5-(6-2)))=10
(9-((6-2)-5))=10
(9-((6-5)-2))=10
(9-(6-(2+5)))=10