(Top Secrets)Cisco 500-452 Exam Real Questions

Study Notes

Subtraction is the inverse operation of addition. It involves finding the difference between two numbers.
To subtract numbers, align the digits vertically, placing the smaller number underneath the larger number.
Subtract the digits in each place value column, starting from the rightmost column. Borrow from the next higher place value if necessary.

When subtracting multi-digit numbers, it's crucial to maintain the correct place values.
Example: To subtract 3456 from 7890, align the digits, and subtract column-by-column.
If a digit in the top number is smaller than the digit below it, regroup (borrow).

Negative numbers are numbers less than zero. They are often represented with a minus sign ("-") in front of the number.
Subtracting a positive number is the same as adding the opposite (negative) number.
Example: 5 - 8 = 5 + (-8) = -3
Subtracting a negative number is the same as adding the positive equivalent.
Example: 5 - (-8) = 5 + 8 = 13

Word problems require applying subtraction to real-world scenarios.
Read the problem carefully to understand the relationship between the numbers and identify what needs to be found.
Example: If John has 15 apples and gives away 7, how many apples does he have left? (15 - 7 = 8)
Translate the problem into an equation (or a model).
Carefully define the variables used in the problem.

Commutative Property (does not apply): Changing the order of the numbers being subtracted changes the result. Subtraction is not commutative. (e.g., 5 - 3 ≠ 3 - 5)
Associative Property (does not apply): The grouping of numbers in a subtraction problem affects the result, so the associative property does not hold for subtraction.
Identity Property: Subtracting zero from a number equals the original number (e.g., 5 - 0 = 5).
Zero Property: When zero is subtracted from a number, the difference is the number itself (e.g., 6 - 0=6).