(ただし1と2を合せて12のような使い方は出来ません。)
35個の解法が見つかりました。
(((8+9)-6)-1)=10
((8+(9-1))-6)=10
((8+(9-6))-1)=10
((8+9)-(1+6))=10
((8-(1-9))-6)=10
((8-(6-9))-1)=10
((8-1)+(9-6))=10
((8-1)-(6-9))=10
((8-6)+(9-1))=10
((8-6)-(1-9))=10
((9+(8-1))-6)=10
((9+(8-6))-1)=10
((9-(1-8))-6)=10
((9-(6-8))-1)=10
((9-1)+(8-6))=10
((9-1)-(6-8))=10
((9-6)+(8-1))=10
((9-6)-(1-8))=10
(8+((9-1)-6))=10
(8+((9-6)-1))=10
(8+(9-(1+6)))=10
(8-((1+6)-9))=10
(8-(1+(6-9)))=10
(8-(1-(9-6)))=10
(8-(6+(1-9)))=10
(8-(6-(9-1)))=10
(9+((8-1)-6))=10
(9+((8-6)-1))=10
(9+(8-(1+6)))=10
(9-((1+6)-8))=10
(9-(1+(6-8)))=10
(9-(1-(8-6)))=10
(9-(6+(1-8)))=10
(9-(6-(8-1)))=10