Multiplying Decimal Numbers and Fractions

Oct 13, 2025 by wbrum.org 117 views

Understanding the Problem

In this problem, we are required to calculate the product of a decimal number and a fraction. The decimal number is 2.35, and the fraction is 2/3. To solve this problem, we need to follow the order of operations (PEMDAS) and multiply the decimal number by the fraction.

Multiplying Decimal Numbers and Fractions

When multiplying a decimal number by a fraction, we can multiply the decimal number by the numerator of the fraction and then divide the result by the denominator of the fraction. In this case, we will multiply 2.35 by 2 and then divide the result by 3.

Step 1: Multiply 2.35 by 2

To multiply 2.35 by 2, we can multiply the decimal number by 2.

2.35 × 2 = 4.70

Step 2: Divide the Result by 3

Now, we need to divide the result by 3.

4.70 ÷ 3 = 1.5667

Converting the Result to a Fraction

To convert the result to a fraction, we can divide the numerator by the denominator.

1.5667 = 15667/10000

Simplifying the Fraction

To simplify the fraction, we can divide both the numerator and the denominator by their greatest common divisor (GCD).

The GCD of 15667 and 10000 is 1.

Therefore, the simplified fraction is:

15667/10000

Choosing the Correct Answer

Now, let's compare the simplified fraction with the answer choices.

A. 7/30 B. 7/15 C. 27/30 D. 47/30

None of the answer choices match the simplified fraction. However, we can convert the fraction to a decimal and compare it with the answer choices.

1.5667 ≈ 1.57

Now, let's convert the answer choices to decimals and compare them with 1.57.

A. 7/30 ≈ 0.2333 B. 7/15 ≈ 0.4667 C. 27/30 ≈ 0.9 D. 47/30 ≈ 1.5667

The correct answer is D. 47/30.

Conclusion

In this problem, we calculated the product of a decimal number and a fraction. We followed the order of operations and multiplied the decimal number by the numerator of the fraction and then divided the result by the denominator of the fraction. We then converted the result to a fraction and simplified it. Finally, we compared the simplified fraction with the answer choices and chose the correct answer.

Key Takeaways

When multiplying a decimal number by a fraction, we can multiply the decimal number by the numerator of the fraction and then divide the result by the denominator of the fraction.
To convert a decimal to a fraction, we can divide the numerator by the denominator.
To simplify a fraction, we can divide both the numerator and the denominator by their greatest common divisor (GCD).
When comparing fractions, we can convert them to decimals and compare the decimals.

Practice Problems

Calculate the product of 3.25 and 1/4.
Calculate the product of 2.75 and 3/5.
Calculate the product of 1.25 and 2/3.

Answer Key

3.25 × 1/4 = 0.8125
2.75 × 3/5 = 1.65
1.25 × 2/3 = 0.8333
Multiplication of Decimal Numbers and Fractions: Q&A =====================================================

Q: What is the order of operations when multiplying a decimal number by a fraction?

A: The order of operations is to multiply the decimal number by the numerator of the fraction and then divide the result by the denominator of the fraction.

Q: How do I convert a decimal to a fraction?

A: To convert a decimal to a fraction, you can divide the numerator by the denominator. For example, to convert 0.5 to a fraction, you can divide 5 by 10, which gives you 1/2.

Q: How do I simplify a fraction?

A: To simplify a fraction, you can divide both the numerator and the denominator by their greatest common divisor (GCD). For example, to simplify 6/8, you can divide both numbers by 2, which gives you 3/4.

Q: What is the greatest common divisor (GCD)?

A: The greatest common divisor (GCD) is the largest number that divides both the numerator and the denominator of a fraction without leaving a remainder.

Q: How do I compare fractions?

A: To compare fractions, you can convert them to decimals and compare the decimals. Alternatively, you can find a common denominator and compare the numerators.

Q: What is a common denominator?

A: A common denominator is a number that both fractions can divide into evenly. For example, to compare 1/2 and 1/3, you can find a common denominator of 6, which gives you 3/6 and 2/6.

Q: How do I find a common denominator?

A: To find a common denominator, you can list the multiples of each denominator and find the smallest multiple that both denominators have in common. Alternatively, you can use the least common multiple (LCM) formula.

Q: What is the least common multiple (LCM)?

A: The least common multiple (LCM) is the smallest number that both numbers can divide into evenly.

Q: How do I use the LCM formula?

A: The LCM formula is:

LCM(a, b) = (a × b) / GCD(a, b)

For example, to find the LCM of 6 and 8, you can plug in the numbers:

LCM(6, 8) = (6 × 8) / GCD(6, 8) = 48 / 2 = 24

Q: What are some common mistakes to avoid when multiplying decimal numbers and fractions?

A: Some common mistakes to avoid include:

Not following the order of operations
Not converting decimals to fractions
Not simplifying fractions
Not finding a common denominator when comparing fractions

Q: How can I practice multiplying decimal numbers and fractions?

A: You can practice multiplying decimal numbers and fractions by working through examples and exercises. You can also use online resources and practice tests to help you prepare for exams and quizzes.

Q: What are some real-world applications of multiplying decimal numbers and fractions?

A: Some real-world applications of multiplying decimal numbers and fractions include:

Calculating discounts and sales tax
Measuring ingredients for recipes
Calculating interest rates and investments
Converting between units of measurement

Q: How can I apply what I've learned to real-world problems?

A: You can apply what you've learned by using the concepts and techniques to solve real-world problems. For example, you can use the order of operations to calculate discounts and sales tax, or use fractions to measure ingredients for recipes.