(ただし1と2を合せて12のような使い方は出来ません。)
21個の解法が見つかりました。
((2+(3×4))-4)=10
((2-4)+(3×4))=10
((3×4)+(2-4))=10
((3×4)-(4-2))=10
((3×4)-(4÷2))=10
((4×4)-(2×3))=10
(2×((4+4)-3))=10
(2×(4+(4-3)))=10
(2×(4-(3-4)))=10
(2+((3×4)-4))=10
(2-(4-(3×4)))=10
(4×(3-(2÷4)))=10
(4×(4-(3÷2)))=10
(4+((3×4)÷2))=10
(4+(3×(4-2)))=10
(4+(3×(4÷2)))=10
(4+(3÷(2÷4)))=10
(4+(4×(3÷2)))=10
(4+(4÷(2÷3)))=10
(4-(3×(2-4)))=10