(ただし1と2を合せて12のような使い方は出来ません。)
30個の解法が見つかりました。
(((7+7)÷1)-4)=10
((1×(7+7))-4)=10
((1×7)+(7-4))=10
((1×7)-(4-7))=10
((7+(1×7))-4)=10
((7+(7-4))÷1)=10
((7+(7÷1))-4)=10
((7+7)-(1×4))=10
((7+7)-(4÷1))=10
((7-(4-7))÷1)=10
((7-4)+(1×7))=10
((7-4)+(7÷1))=10
((7÷1)+(7-4))=10
((7÷1)-(4-7))=10
(1×((7+7)-4))=10
(1×(7+(7-4)))=10
(1×(7-(4-7)))=10
(7+((1×7)-4))=10
(7+((7-4)÷1))=10
(7+((7÷1)-4))=10
(7+(1×(7-4)))=10
(7+(7-(1×4)))=10
(7+(7-(4÷1)))=10
(7-((1×4)-7))=10
(7-((4-7)÷1))=10
(7-((4÷1)-7))=10
(7-(1×(4-7)))=10
(7-(4-(1×7)))=10
(7-(4-(7÷1)))=10