THE DIGITAL CENTURY
There are several solutions to this puzzle and so I
will list several
with the number of signs and strokes so that you can compare.
1+2+3+4+5+6+7+(8X9)=100 9 signs 18 strokes.....This is the answer usually published.
-(1X2)-3-4-5+(6X7)+(8X9)=100 12 signs 20 strokes
1+(2X3)+(4X5)-6+7+(8X9)=100 11 signs 21 strokes
(1+2-3-4)(5-6-7-8-9)=100 9 signs 12 strokes
1+(2X3)+4+5+67+8+9=100 8 signs 16 strokes
(1X2)+34+56+7-8+9=100 7 signs 13 strokes
12+3-4+5+67+8+9=100 6 signs 11 strokes
123-4-5-6-7+8-9=100 6 signs 7 strokes
123+4-5+67-8-9=100 4 signs 6 strokes
123+45-67+8-9=100 4 signs 6 strokes
123-45-67+89=100 3 signs 4 strokes