What is negative 4 minus negative 20?

Negative 4 minus negative 20 can be written as follows in mathematical terms:

(-4) - (-20)

That is a lot of negatives! With all the minus signs it may be confusing to figure out how to subtract a negative number from another negative number.

Don't dispair. We will explain how to solve negative 4 minus negative 20 so you understand the problem and can easily solve similar problems in the future.

Start by picturing a number line that goes to negative infinity on the left side of 0 and positive infinity on the right side of 0:

∞ ..... -3, -2, -1, 0, +1, +2, +3, .... ∞

Looking at the number line above, we can make the following observations:

Adding a positive number goes to the right.
Adding a negative number goes to the left.

Adding and subtracting cannot go in the same direction on a number line. Therefore, this must also be true:

Subtracting a positive number goes to the left.
Subtracting a negative number goes to the right.

Thus, with the problem negative 4 minus negative 20, we are subtracting a negative number and we go to the right. Specifically, we go 20 "spaces" to the right from -4 to +16 on the number line.

Here is negative 4 minus negative 20 displayed with the answer per the explanation above:

(-4) - (-20) = 16

Negative Minus Negative Calculator
Get the answer to another negative number minus negative number problem here!

What is negative 4 minus negative 21?
Here is a similar negative minus negative problem that we explained and solved.