（ただし１と２を合せて１２のような使い方は出来ません。）
53個の解法が見つかりました。
((2+8)×(9÷9))=10
((2+8)+(9-9))=10
((2+8)-(9-9))=10
((2+8)÷(9÷9))=10
((2+9)+(8-9))=10
((2+9)-(9-8))=10
((2-9)+(8+9))=10
((8+(2+9))-9)=10
((8+9)+(2-9))=10
((8+9)-(9-2))=10
((8-9)+(2+9))=10
((9×(2+8))÷9)=10
((9+(2+8))-9)=10
((9-9)+(2+8))=10
((9÷9)×(2+8))=10
(2+((8×9)÷9))=10
(2+((8+9)-9))=10
(2+(8×(9÷9)))=10
(2+(8+(9-9)))=10
(2+(8-(9-9)))=10
(2+(8÷(9÷9)))=10
(2+(9×(8÷9)))=10
(2+(9+(8-9)))=10
(2+(9-(9-8)))=10
(2+(9÷(9÷8)))=10
(2-((9-8)-9))=10
(2-((9-9)-8))=10
(2-(9-(8+9)))=10
(8+((2×9)÷9))=10
(8+((2+9)-9))=10
(8+(2×(9÷9)))=10
(8+(2+(9-9)))=10
(8+(2-(9-9)))=10
(8+(2÷(9÷9)))=10
(8+(9×(2÷9)))=10
(8+(9+(2-9)))=10
(8+(9-(9-2)))=10
(8+(9÷(9÷2)))=10
(8-((9-2)-9))=10
(8-((9-9)-2))=10
(8-(9-(2+9)))=10
(9×((2+8)÷9))=10
(9×(2-(8÷9)))=10
(9+((2+8)-9))=10
(9+(2+(8-9)))=10
(9+(2-(9-8)))=10
(9+(8+(2-9)))=10
(9+(8-(9-2)))=10
(9-((9-2)-8))=10
(9-((9-8)-2))=10
(9-(9-(2+8)))=10
(9÷(9÷(2+8)))=10