Nadine has a chip board with 4 red chips. She needs to subtract 2 black chips, but there are no black chips on the board. Nadine says" It is impossible to subtract 2 black chips. There are none on the boars!" What can Nadine do to the chip bound so that she can subtract 2 black chips? Explain your reasoning.

To help Nadine subtract 2 black chips when there are none on the board, she can use a strategy called "virtual subtraction". Here's how it works:

1. Start with the original chip board, which has 4 red chips.
2. Since there are no black chips to subtract, we can imagine or pretend that there are 2 black chips on the board, making a total of 6 chips in total (4 red + 2 black).
3. Now, Nadine can subtract the 2 imaginary (or virtual) black chips from the board.
- Subtracting 2 imaginary black chips from the 6 chips on the board leaves us with 4 red chips (6 - 2 = 4).
4. Even though there were no black chips on the board to begin with, we effectively subtracted 2 black chips through the concept of virtual subtraction.
- Nadine can now correctly say that she subtracted 2 black chips.

In short, Nadine can use the concept of virtual or imaginary chips to perform the subtraction of 2 black chips, even if there are no actual black chips on the board.