Subtraction involves taking away or subtracting one quantity from another. It can be shown by using objects like balloons, on a number line, or through vertical subtraction with or without borrowing. Basic subtraction means taking away and finding the difference or amount remaining. More complex subtraction may require borrowing from neighboring digits when the digit being subtracted is larger, such as 34 - 16 = 18 through borrowing a ten from the three tens place.