（ただし１と２を合せて１２のような使い方は出来ません。）
37個の解法が見つかりました。
((2+4)+(9-5))=10
((2+4)-(5-9))=10
((2+9)+(4-5))=10
((2+9)-(5-4))=10
((2-5)+(4+9))=10
((4+(2+9))-5)=10
((4+9)+(2-5))=10
((4+9)-(5-2))=10
((4-5)+(2+9))=10
((9+(2+4))-5)=10
((9-5)+(2+4))=10
(2+((4+9)-5))=10
(2+(4+(9-5)))=10
(2+(4-(5-9)))=10
(2+(9+(4-5)))=10
(2+(9-(5-4)))=10
(2-((5-4)-9))=10
(2-((5-9)-4))=10
(2-(5-(4+9)))=10
(4+((2+9)-5))=10
(4+(2+(9-5)))=10
(4+(2-(5-9)))=10
(4+(9+(2-5)))=10
(4+(9-(5-2)))=10
(4-((5-2)-9))=10
(4-((5-9)-2))=10
(4-(5-(2+9)))=10
(5÷((9÷2)-4))=10
(9+((2+4)-5))=10
(9+(2+(4-5)))=10
(9+(2-(5-4)))=10
(9+(4+(2-5)))=10
(9+(4-(5-2)))=10
(9-((5-2)-4))=10
(9-((5-4)-2))=10
(9-(5-(2+4)))=10