(ただし1と2を合せて12のような使い方は出来ません。)
19個の解法が見つかりました。
((2+8)×(2-1))=10
((2+8)÷(2-1))=10
((2-1)×(2+8))=10
((2÷2)+(1+8))=10
(1+(8+(2÷2)))=10
(2×((8-1)-2))=10
(2×((8-2)-1))=10
(2×(1+(8÷2)))=10
(2×(8-(1+2)))=10
(2+(8×(2-1)))=10
(2+(8÷(2-1)))=10
(2-(8×(1-2)))=10
(2-(8÷(1-2)))=10
(8+(1+(2÷2)))=10
(8+(2×(2-1)))=10
(8+(2÷(2-1)))=10
(8-(2×(1-2)))=10
(8-(2÷(1-2)))=10