(ただし1と2を合せて12のような使い方は出来ません。)
18個の解法が見つかりました。
((5+(5+5))-5)=10
((5+5)×(5÷5))=10
((5+5)+(5-5))=10
((5+5)-(5-5))=10
((5+5)÷(5÷5))=10
((5-5)+(5+5))=10
((5÷5)×(5+5))=10
(5×((5+5)÷5))=10
(5+((5×5)÷5))=10
(5+((5+5)-5))=10
(5+(5×(5÷5)))=10
(5+(5+(5-5)))=10
(5+(5-(5-5)))=10
(5+(5÷(5÷5)))=10
(5-((5-5)-5))=10
(5-(5-(5+5)))=10
(5÷(5÷(5+5)))=10