Problem 159 - Prealgebra

Question

In the following exercises, subtract and then check by adding. $$9-4$$

Step-by-Step Solution

Answer

9 - 4 = 5. Checked: 5 + 4 = 9.

Step 1: Perform the Subtraction

Subtract 4 from 9. Start by writing the subtraction as: 9 - 4 Calculate the result: 9 - 4 = 5

Step 2: Check by Adding

To ensure the subtraction is correct, add the result (5) to the number subtracted (4). Write the addition equation: 5 + 4 Calculate the result to verify: 5 + 4 = 9 Since the sum is equal to the original number (9), the subtraction is verified to be correct.

Key Concepts

subtraction verification

Subtraction verification is an essential step to ensure the accuracy of your arithmetic operations. When you perform a subtraction, like in the example 9 - 4, you should always verify your result. This involves taking the result of your subtraction and performing the opposite operation (addition) to see if it matches your original number.

For instance, after calculating 9 - 4 = 5, you would then add the result (5) back to the subtracted number (4). If 5 + 4 brings you back to the original number 9, then your subtraction is correct. This simple check helps prevent mistakes and ensures that you have the right answer.

arithmetic operations

Arithmetic operations are the basic building blocks of math. They include addition, subtraction, multiplication, and division. Each operation has specific rules and techniques to follow.
Understanding these operations is crucial for solving more complex math problems.
In the context of subtraction, you take one number away from another. Like in the given example, 9 - 4, you start with 9 and remove 4 from it.
By mastering these basic operations, you can build a strong foundation for advancing in mathematics.

addition for checking subtraction

Addition for checking subtraction is a reliable method to confirm your subtraction results. After performing a subtraction operation, such as 9 - 4 = 5, you can ensure accuracy by performing an addition.
Here’s how you do it:

• Take the result of the subtraction (in this case, 5).
• Add the subtracted number (4) to the result.
• Check if the sum equals the original number (9).

If the sum matches the initial number, it means your subtraction was done correctly. This method not only helps in double-checking your work but also reinforces the relationship between addition and subtraction.