（ただし１と２を合せて１２のような使い方は出来ません。）
61個の解法が見つかりました。
((1+(5+9))-5)=10
((1+5)+(9-5))=10
((1+5)-(5-9))=10
((1+9)×(5÷5))=10
((1+9)+(5-5))=10
((1+9)-(5-5))=10
((1+9)÷(5÷5))=10
((1-5)+(5+9))=10
((5×(1+9))÷5)=10
((5+(1+9))-5)=10
((5+9)+(1-5))=10
((5+9)-(5-1))=10
((5-5)+(1+9))=10
((5÷5)×(1+9))=10
((5÷5)+(1×9))=10
((5÷5)+(9÷1))=10
((9+(1+5))-5)=10
((9+(5÷5))÷1)=10
((9-5)+(1+5))=10
((9÷1)+(5÷5))=10
(1×(9+(5÷5)))=10
(1+((5×9)÷5))=10
(1+((5+9)-5))=10
(1+(5×(9÷5)))=10
(1+(5+(9-5)))=10
(1+(5-(5-9)))=10
(1+(5÷(5÷9)))=10
(1+(9×(5÷5)))=10
(1+(9+(5-5)))=10
(1+(9-(5-5)))=10
(1+(9÷(5÷5)))=10
(1-((5-5)-9))=10
(1-((5-9)-5))=10
(1-(5-(5+9)))=10
(5×((1+9)÷5))=10
(5+((1+9)-5))=10
(5+(1+(9-5)))=10
(5+(1-(5-9)))=10
(5+(9+(1-5)))=10
(5+(9-(5-1)))=10
(5-((5-1)-9))=10
(5-((5-9)-1))=10
(5-(5-(1+9)))=10
(5÷(5÷(1+9)))=10
(9+((1×5)÷5))=10
(9+((1+5)-5))=10
(9+((5÷1)÷5))=10
(9+((5÷5)÷1))=10
(9+(1×(5÷5)))=10
(9+(1+(5-5)))=10
(9+(1-(5-5)))=10
(9+(1÷(5÷5)))=10
(9+(5×(1÷5)))=10
(9+(5+(1-5)))=10
(9+(5-(5-1)))=10
(9+(5÷(1×5)))=10
(9+(5÷(5÷1)))=10
(9-((5-1)-5))=10
(9-((5-5)-1))=10
(9-(5-(1+5)))=10