Understanding PEMDAS: Solving Math Expressions with Parentheses, Multiplication, and Subtraction

Are you struggling to solve math expressions like 15 - 6 - 4 times; 2? Follow the order of operations, often remembered by the acronym PEMDAS, to ensure you get the correct answer. This article will guide you through the process, including an example and practical tips for using PEMDAS in everyday math problems.

What is PEMDAS?

The order of operations, also known as PEMDAS, is a set of rules that dictate the sequence in which mathematical operations should be performed to obtain the correct result. PEMDAS stands for:

Parentheses Exponents Multiplication and Division Addition and Subtraction

These components of PEMDAS are important for solving complex mathematical expressions quickly and accurately. Let's apply this knowledge to the expression: 15 - 6 - 4 times; 2.

How to Solve the Expression 15 - 6 - 4 times; 2

Step 1: Parentheses

The expression 15 - 6 - 4 times; 2 does not have any parentheses, so we can move directly to the next step.

Step 2: Exponents

There are no exponents in the expression, so we can proceed without any issues.

Step 3: Multiplication and Division

According to PEMDAS, we should perform multiplication before subtraction. So, let's first deal with the multiplication:

4 times; 2 8

Substitute this result into the original expression:

15 - 6 - 8

Step 4: Addition and Subtraction

PEMDAS states that we perform addition and subtraction from left to right. So, let's do the operations from left to right:

15 - 6 9 9 - 8 1

Therefore, the final answer is:

1

Using PEMDAS in Everyday Life

Understanding PEMDAS can be incredibly useful in everyday life, especially when dealing with financial calculations or scientific formulas. Here’s a simple example to demonstrate how it can be applied:

Example:

Calculate the total cost of buying 3 items priced at $5, $15, and $10 after a 20% discount. Total cost 5 - 15 - 10 times; (1 - 0.20) 5 - 15 - 10 times; 0.80 10 times; 0.80 8 (This represents the discounted price of $10) Now the expression is: 5 - 15 - 8 5 - 15 -10 -10 - 8 -18

No, wait! We misunderstood it. Apply PEMDAS:

5 - 15 -10 -10 - 8 -18 (should be 5 - 15 - 8 -18, but logically, there’s a double-negative or miss placement of parentheses)

The final price should be:

$10 (Correctly calculated as 5 - 15 - 8 -10 - 8 -18, but since it’s a purchase, the logical result is $10)

Conclusion

Mastery of PEMDAS is crucial for accurately solving math problems. By adhering to the PEMDAS order, you can ensure that your calculations are correct, whether you’re solving simple expressions or complex equations. Practicing with various examples and applying PEMDAS can significantly enhance your math skills.