(ただし1と2を合せて12のような使い方は出来ません。)
20個の解法が見つかりました。
(((9+9)-6)-2)=10
((9+(9-2))-6)=10
((9+(9-6))-2)=10
((9+9)-(2+6))=10
((9-(2-9))-6)=10
((9-(6-9))-2)=10
((9-2)+(9-6))=10
((9-2)-(6-9))=10
((9-6)+(9-2))=10
((9-6)-(2-9))=10
(2×(6-(9÷9)))=10
(9+((9-2)-6))=10
(9+((9-6)-2))=10
(9+(9-(2+6)))=10
(9-((2+6)-9))=10
(9-(2+(6-9)))=10
(9-(2-(9-6)))=10
(9-(6+(2-9)))=10
(9-(6-(9-2)))=10