What is -189.987-30.87.

-189.987 - 30.87 = -220.857

To find the value of -189.987 minus 30.87, follow these steps:

Step 1: Subtract the two decimal numbers without considering the signs:
-189.987 - 30.87 = 159.117

Step 2: Determine the sign of the result:
Since the first number (-189.987) is negative, the result will be negative.

Step 3: Combine the sign and the result:
Therefore, -189.987 - 30.87 = -159.117.