（ただし１と２を合せて１２のような使い方は出来ません。）
52個の解法が見つかりました。
((2+(3+9))-4)=10
((2+3)+(9-4))=10
((2+3)-(4-9))=10
((2+9)+(3-4))=10
((2+9)-(4-3))=10
((2-4)+(3+9))=10
((3+(2+9))-4)=10
((3+9)+(2-4))=10
((3+9)-(4-2))=10
((3+9)-(4÷2))=10
((3-4)+(2+9))=10
((4×(9÷3))-2)=10
((4÷(3÷9))-2)=10
((9×(4÷3))-2)=10
((9+(2+3))-4)=10
((9-4)+(2+3))=10
((9÷(3÷4))-2)=10
(2+((3+9)-4))=10
(2+(3+(9-4)))=10
(2+(3-(4-9)))=10
(2+(9+(3-4)))=10
(2+(9-(4-3)))=10
(2-((4-3)-9))=10
(2-((4-9)-3))=10
(2-(4-(3+9)))=10
(3+((2+9)-4))=10
(3+(2+(9-4)))=10
(3+(2-(4-9)))=10
(3+(9+(2-4)))=10
(3+(9-(4-2)))=10
(3+(9-(4÷2)))=10
(3-((4-2)-9))=10
(3-((4-9)-2))=10
(3-((4÷2)-9))=10
(3-(4-(2+9)))=10
(4+((2×9)÷3))=10
(4+((3+9)÷2))=10
(4+(2×(9÷3)))=10
(4+(2÷(3÷9)))=10
(4+(9×(2÷3)))=10
(4+(9÷(3÷2)))=10
(9+((2+3)-4))=10
(9+(2+(3-4)))=10
(9+(2-(4-3)))=10
(9+(3+(2-4)))=10
(9+(3-(4-2)))=10
(9+(3-(4÷2)))=10
(9-((4-2)-3))=10
(9-((4-3)-2))=10
(9-((4÷2)-3))=10
(9-(4-(2+3)))=10