（ただし１と２を合せて１２のような使い方は出来ません。）
50個の解法が見つかりました。
(((9+9)-8)÷1)=10
(((9+9)÷1)-8)=10
((1×(9+9))-8)=10
((1×9)+(9-8))=10
((1×9)-(8-9))=10
((1+8)+(9÷9))=10
((1+9)×(9-8))=10
((1+9)÷(9-8))=10
((9+(1×9))-8)=10
((9+(9-8))÷1)=10
((9+(9÷1))-8)=10
((9+9)-(1×8))=10
((9+9)-(8÷1))=10
((9-(8-9))÷1)=10
((9-8)×(1+9))=10
((9-8)+(1×9))=10
((9-8)+(9÷1))=10
((9÷1)+(9-8))=10
((9÷1)-(8-9))=10
((9÷9)+(1+8))=10
(1×((9+9)-8))=10
(1×(9+(9-8)))=10
(1×(9-(8-9)))=10
(1+(8+(9÷9)))=10
(1+(9×(9-8)))=10
(1+(9÷(9-8)))=10
(1-(9×(8-9)))=10
(1-(9÷(8-9)))=10
(8+(1+(9÷9)))=10
(9+((1×9)-8))=10
(9+((1+8)÷9))=10
(9+((9-1)÷8))=10
(9+((9-8)÷1))=10
(9+((9÷1)-8))=10
(9+(1×(9-8)))=10
(9+(1÷(9-8)))=10
(9+(8÷(9-1)))=10
(9+(9-(1×8)))=10
(9+(9-(8÷1)))=10
(9+(9÷(1+8)))=10
(9-((1×8)-9))=10
(9-((1-9)÷8))=10
(9-((8-9)÷1))=10
(9-((8÷1)-9))=10
(9-(1×(8-9)))=10
(9-(1÷(8-9)))=10
(9-(8-(1×9)))=10
(9-(8-(9÷1)))=10
(9-(8÷(1-9)))=10