Fill in each of the empty spaces between the numbers in the following series with symbols \((+-\div\)\) and \(\times\) (use each symbol only once and no parenthesis). What is the least possible value of the result? \(1\_3\_5\_7\_9 = ?\)

Explanation: To get the least value, we need to subtract the largest possible value and add the least possible value. So, placing a multiplication sign between 7 and 9 gives us 63 . Then, we place a minus sign before that to make it -63 . For the remaining blanks, \(1+3/5=1.6\) and \(1/3+5=5.33\). So, the division sign should be placed between 3 and 5 , and the addition sign should be placed after 1 . Thus, we get \(1 + 3\div5 - 7\times9 = 1 + 0.6 - 63 = 1.6 - 63 = -61.4\).