1. The problem is to convert a positive number, such as 19.64, into its negative equivalent in Excel. 2. The formula to convert a positive number to negative is to multiply the number by $-1$. 3. In Excel, you can use the formula: =-ABS(A1) where A1 contains the positive number. 4. Explanation: ABS(A1) returns the absolute value (positive) of the number in A1, and the negative sign in front converts it to negative. 5. For example, if A1 = 19.64, then =-ABS(A1) will return $-19.64$. 6. This method ensures that even if the number is already negative, it will still return the negative value.