(ただし1と2を合せて12のような使い方は出来ません。)
22個の解法が見つかりました。
((2×4)+(1×2))=10
((2×4)+(2÷1))=10
((2+(2×4))÷1)=10
((2÷1)+(2×4))=10
((4×(1+2))-2)=10
(1×(2+(2×4)))=10
(2×((2+4)-1))=10
(2×(2+(4-1)))=10
(2×(2-(1-4)))=10
(2×(4+(2-1)))=10
(2×(4-(1-2)))=10
(2+((2×4)÷1))=10
(2+(1×(2×4)))=10
(2+(2×(1×4)))=10
(2+(2×(4÷1)))=10
(2+(2÷(1÷4)))=10
(2+(4×(1×2)))=10
(2+(4×(2÷1)))=10
(2+(4÷(1÷2)))=10
(4×(2+(1÷2)))=10
(4+(2×(1+2)))=10