Final answer:
To add four more pieces to a pattern, you would use addition to add the four pieces and subtraction to remove any pieces that are not needed.
Step-by-step explanation:
The correct answer is D) Subtraction and addition.
To add four more pieces to a pattern, you would use addition to add the four pieces and subtraction to remove any pieces that are not needed.
For example, if the pattern already has 8 pieces and you want to add 4 more, you would start with 8 and add 4, resulting in a total of 12 pieces.
Learn more about Algebraic rules