Problem 164 In the following exercises, subt... [FREE SOLUTION]

91影视

Prealgebra

Lynn Marecek, MaryAnne Anthony-Smith

$Math Studyset 91影视 Explanations$ Math

2016 Edition

Chapter 1: Problem 164

In the following exercises, subtract and then check by adding. $$45-21$$

Short Answer

Expert verified

The result of 45 - 21 is 24, and adding 24 to 21 gives 45.

Step by step solution

Subtract the numbers

Start with the given numbers: 45 and 21. Subtract 21 from 45.\[ 45 - 21 = 24 \]

Check the result by adding

To confirm the subtraction result, add the difference (24) to the smaller number (21). The sum should equal the original larger number (45).\[ 24 + 21 = 45 \]

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Key Concepts

These are the key concepts you need to understand to accurately answer the question.

checking subtraction with addition

When you subtract two numbers, you can check if your result is correct by using addition.
This method helps in verifying that the subtraction was done correctly. In our example, we subtracted 21 from 45 and got 24.
To be sure that 24 is the correct answer, we add 24 back to the smaller number, which is 21. If the result is the original number, which is 45, our subtraction is correct.
To sum up, the process looks like this:

Perform the subtraction: $ 45 - 21 = 24 $
Verify by addition: $ 24 + 21 = 45 $

This method of checking subtraction with addition is very useful and reliable, making sure that mistakes are caught early.

elementary arithmetic

Elementary arithmetic includes the basic operations of addition, subtraction, multiplication, and division.
These are the building blocks of all math. Learning these operations well is crucial as they are used in many daily activities and in advanced math topics.
In our example, subtraction was used first followed by addition to check the result. Knowing basic arithmetic helps in understanding more complex math problems.
This is why it's important to practice these basic operations regularly.

subtraction verification

Subtraction verification is a method to ensure that your subtraction is correct. It usually involves adding the subtracted amount back to the result to see if you get the original number.
In our example, we subtracted 21 from 45 and got 24. To make sure this is right, we add 24 to 21. If the sum is 45,
then our subtraction was correct. Verification steps:

Subtract: $ 45 - 21 = 24 $
Add back: $ 24 + 21 = 45 $
Compare result with the original number

This process helps to avoid errors and confirms the correctness of your calculations.

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91影视

In the following exercises, subtract and then check by adding. $$45-21$$

Short Answer

Step by step solution

Subtract the numbers

Check the result by adding

Key Concepts

checking subtraction with addition

elementary arithmetic

subtraction verification

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