Problem 39 - Algebra 1

Question

Find the sum. Use a calculator if you wish. $$20.37+190.8+(-85.13)$$

Step-by-Step Solution

Answer

The sum of 20.37, 190.8, and -85.13 is 126.04

Step 1: Identify the Numbers

We have been given three numbers: 20.37, 190.8, and -85.13. It should be noted that -85.13 is a negative number.

Step 2: Add The Positive Numbers

Add the positive numbers 20.37 and 190.8. This operation will give us \(20.37 + 190.8 = 211.17\)

Step 3: Add The Negative Number

Now add the negative number to the sum from the previous step. The operation will be \(211.17 + (-85.13) = 126.04\)

Key Concepts

Addition

Addition is one of the fundamental concepts in arithmetic. It involves combining two or more numbers to get a total sum. In the exercise given, you are tasked with finding the sum of three numbers.

Here's a quick breakdown of addition:

• Identify the numbers: The exercise involves 20.37, 190.8, and -85.13.
• Combine the numbers: You're simply bringing numbers together by stacking or lining them up, usually in columns, particularly when dealing without a calculator.

Understanding addition helps in solving complex mathematical problems and is highly applicable in everyday situations like budgeting and shopping. Simple, right?

Negative Numbers

The concept of negative numbers can sometimes confuse students. However, it’s quite simple once you understand it. Negative numbers are values less than zero. They are denoted with a minus sign (e.g., -85.13 in the exercise).

Here’s what you need to know about negative numbers:

• Subtracting a positive: Effectively, adding a negative is the same as subtracting the number's positive counterpart. For example, adding -85.13 is like subtracting 85.13.
• Balance in equations: Negative numbers are often used to represent debt or loss in real-world applications.
• Direction in math: Think of them as a direction on a number line, where moving left from zero is going negative.

Grasping negative numbers is critical because they are frequently used in both math and science.

Use of Calculator

In mathematics, calculators are valuable tools that simplify computations and reduce errors. They are incredibly helpful when dealing with decimals or a long list of numbers, such as in our exercise. Calculators assist in performing operations accurately and quickly.

When using a calculator:

• Input carefully: Double-check your inputs to ensure accuracy.
• Check functions: Familiarize yourself with basic functions and operations such as addition, subtraction, multiplication, and division.
• Re-examine results: Always verify the calculator's output with a mental estimation or re-inputting the numbers.

Using calculators can enhance understanding of lengthy calculations, but it's essential to also develop mental math skills for smaller calculations.