Choosing the Correct Number

Oct 13, 2025 by wbrum.org 138 views

Introduction

When solving equations, it's often helpful to eliminate decimals to make calculations easier and more accurate. In this article, we'll explore how to eliminate decimals in equations by multiplying each term by a suitable number. We'll use a specific equation as an example to demonstrate the process.

Understanding the Problem

The given equation is:

${ m + 0.02 + 2.1m = -1.45 - 4.81m }$

Our goal is to eliminate the decimals in this equation by multiplying each term by a suitable number.

Identifying the Decimals

Let's identify the decimals in the equation:

0.02
2.1
-1.45
-4.81

Multiplying Each Term

To eliminate the decimals, we need to multiply each term by a number that will make the decimals disappear. Let's analyze each term:

m: This term is already in its simplest form, so we don't need to multiply it.
0.02: To eliminate the decimal, we can multiply this term by 100, since 0.02 * 100 = 2.
2.1m: To eliminate the decimal, we can multiply this term by 10, since 2.1 * 10 = 21.
-1.45: To eliminate the decimal, we can multiply this term by 100, since -1.45 * 100 = -145.
-4.81m: To eliminate the decimal, we can multiply this term by 10, since -4.81 * 10 = -48.1.

Choosing the Correct Number

Now that we've analyzed each term, we need to choose the correct number to multiply each term by. Let's look at the options:

A. 0.01
B. 0.1
C. 10
D. 100

Based on our analysis, we can see that multiplying each term by 100 will eliminate the decimals.

Conclusion

In conclusion, to eliminate the decimals in the given equation, we can multiply each term by 100. This will make the calculations easier and more accurate.

Final Answer

The correct answer is:

D. 100

Example Use Case

Here's an example use case:

Suppose we have the equation:

${ x + 0.05 + 3.2x = -2.15 - 6.8x }$

To eliminate the decimals, we can multiply each term by 100, just like in the previous example. This will give us:

${ 100x + 5 + 320x = -215 - 680x }$

Now we can solve the equation using the standard methods.

Tips and Variations

Here are some tips and variations:

Rounding decimals: If the decimals are not too large, we can round them to the nearest whole number. For example, 0.02 can be rounded to 0.
Using fractions: Instead of multiplying each term by a number, we can use fractions to eliminate the decimals. For example, we can multiply each term by 1/0.02 to eliminate the decimal in the term 0.02.
Using algebraic manipulations: We can use algebraic manipulations to eliminate the decimals. For example, we can add or subtract terms to eliminate the decimals.

Conclusion

Q: What is the purpose of eliminating decimals in equations?

A: The purpose of eliminating decimals in equations is to make calculations easier and more accurate. By eliminating decimals, we can avoid errors and make the calculations more straightforward.

Q: How do I know which number to multiply each term by to eliminate decimals?

A: To determine which number to multiply each term by, you need to analyze each term and identify the decimal. Then, you can multiply the term by a number that will make the decimal disappear. For example, if a term has a decimal of 0.02, you can multiply it by 100 to eliminate the decimal.

Q: Can I use fractions to eliminate decimals instead of multiplying by a number?

A: Yes, you can use fractions to eliminate decimals instead of multiplying by a number. For example, if a term has a decimal of 0.02, you can multiply it by 1/0.02 to eliminate the decimal.

Q: How do I know if I have eliminated all the decimals in an equation?

A: To determine if you have eliminated all the decimals in an equation, you need to check each term and make sure that there are no decimals left. You can do this by looking at each term and checking if it has a decimal. If it does, you need to multiply it by a number that will make the decimal disappear.

Q: Can I use algebraic manipulations to eliminate decimals instead of multiplying by a number?

A: Yes, you can use algebraic manipulations to eliminate decimals instead of multiplying by a number. For example, you can add or subtract terms to eliminate the decimals.

Q: What are some common mistakes to avoid when eliminating decimals in equations?

A: Some common mistakes to avoid when eliminating decimals in equations include:

Not checking each term for decimals
Not multiplying each term by the correct number to eliminate the decimal
Not using algebraic manipulations to eliminate decimals
Not checking the equation for errors after eliminating decimals

Q: How do I check the equation for errors after eliminating decimals?

A: To check the equation for errors after eliminating decimals, you need to:

Review each term to make sure that it has been multiplied by the correct number to eliminate the decimal
Check the equation for any errors or inconsistencies
Use algebraic manipulations to simplify the equation and make it easier to solve

Q: Can I use a calculator to eliminate decimals in equations?

A: Yes, you can use a calculator to eliminate decimals in equations. However, it's always a good idea to double-check your work and make sure that the calculator is giving you the correct answer.

Q: How do I know if I have eliminated all the decimals in a complex equation?

A: To determine if you have eliminated all the decimals in a complex equation, you need to:

Break down the equation into smaller parts
Check each part for decimals
Multiply each part by the correct number to eliminate the decimal
Use algebraic manipulations to simplify the equation and make it easier to solve

Conclusion

In conclusion, eliminating decimals in equations is an important skill that can make calculations easier and more accurate. By following the steps outlined in this article, you can eliminate decimals in equations and solve them using standard methods. Remember to always check your work and make sure that you have eliminated all the decimals in the equation.