Reducing Fractions to the Lowest Terms

Oct 13, 2025 by wbrum.org 109 views

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Introduction

In mathematics, fractions are a way to represent a part of a whole. They are used to express a value that is not a whole number. A fraction consists of two parts: the numerator and the denominator. The numerator is the number on top, and the denominator is the number on the bottom. In this article, we will discuss how to reduce fractions to their lowest terms and how to multiply fractions.

Reducing Fractions to the Lowest Terms

Reducing a fraction to its lowest terms means simplifying it by dividing both the numerator and the denominator by their greatest common divisor (GCD). The GCD is the largest number that divides both the numerator and the denominator without leaving a remainder.

Example 1: Reducing the Fraction $\frac{36}{72}$

To reduce the fraction $\frac{36}{72}$ , we need to find the GCD of 36 and 72. The factors of 36 are 1, 2, 3, 4, 6, 9, 12, 18, and 36. The factors of 72 are 1, 2, 3, 4, 6, 8, 9, 12, 18, 24, 36, and 72. The greatest common factor of 36 and 72 is 36. Therefore, we can divide both the numerator and the denominator by 36 to get:

\frac{36}{72} = \frac{36 \div 36}{72 \div 36} = \frac{1}{2}

Example 2: Reducing the Fraction $\frac{18}{20}$

To reduce the fraction $\frac{18}{20}$ , we need to find the GCD of 18 and 20. The factors of 18 are 1, 2, 3, 6, 9, and 18. The factors of 20 are 1, 2, 4, 5, 10, and 20. The greatest common factor of 18 and 20 is 2. Therefore, we can divide both the numerator and the denominator by 2 to get:

\frac{18}{20} = \frac{18 \div 2}{20 \div 2} = \frac{9}{10}

Example 3: Reducing the Fraction $\frac{144}{156}$

To reduce the fraction $\frac{144}{156}$ , we need to find the GCD of 144 and 156. The factors of 144 are 1, 2, 3, 4, 6, 8, 9, 12, 16, 18, 24, 36, 48, 72, and 144. The factors of 156 are 1, 2, 3, 4, 6, 12, 13, 26, 39, 52, 78, and 156. The greatest common factor of 144 and 156 is 12. Therefore, we can divide both the numerator and the denominator by 12 to get:

\frac{144}{156} = \frac{144 \div 12}{156 \div 12} = \frac{12}{13}

Example 4: Reducing the Fraction $\frac{288}{512}$

To reduce the fraction $\frac{288}{512}$ , we need to find the GCD of 288 and 512. The factors of 288 are 1, 2, 3, 4, 6, 8, 9, 12, 16, 18, 24, 32, 36, 48, 64, 72, 96, 144, 192, and 288. The factors of 512 are 1, 2, 4, 8, 16, 32, 64, 128, and 512. The greatest common factor of 288 and 512 is 64. Therefore, we can divide both the numerator and the denominator by 64 to get:

\frac{288}{512} = \frac{288 \div 64}{512 \div 64} = \frac{9}{16}

Multiplying Fractions

To multiply fractions, we simply multiply the numerators together and multiply the denominators together.

Example: Multiplying $\frac{1}{5}$ by a Number to Get 15

To multiply $\frac{1}{5}$ by a number to get 15, we need to find the number that, when multiplied by $\frac{1}{5}$ , gives us 15. Let's call this number $x$ . We can set up the equation:

\frac{1}{5} \cdot x = 15

To solve for $x$ , we can multiply both sides of the equation by 5:

x = 15 \cdot 5

x = 75

Therefore, we need to multiply $\frac{1}{5}$ by 75 to get 15.

Conclusion

In this article, we discussed how to reduce fractions to their lowest terms and how to multiply fractions. We provided examples of reducing fractions to their lowest terms and multiplying fractions. We also discussed how to multiply a fraction by a number to get a specific value. By following these steps, you can simplify fractions and perform multiplication operations with ease.

Check Your Understanding

Reduce the fraction $\frac{24}{30}$ to its lowest terms.
Multiply the fraction $\frac{3}{4}$ by 2.
Reduce the fraction $\frac{120}{180}$ to its lowest terms.
Multiply the fraction $\frac{2}{3}$ by 9.

Answer Key

$\frac{24}{30} = \frac{4}{5}$
$\frac{3}{4} \cdot 2 = \frac{6}{4} = \frac{3}{2}$
$\frac{120}{180} = \frac{2}{3}$
$\frac{2}{3} \cdot 9 = \frac{18}{3} = 6$

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Q: What is the greatest common divisor (GCD) and how is it used in reducing fractions?

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. It is used in reducing fractions to their lowest terms by dividing both the numerator and the denominator by their GCD.

Q: How do I find the GCD of two numbers?

A: To find the GCD of two numbers, you can list the factors of each number and find the largest factor that they have in common. Alternatively, you can use the Euclidean algorithm to find the GCD.

Q: What is the difference between reducing a fraction and simplifying a fraction?

A: Reducing a fraction means dividing both the numerator and the denominator by their GCD to simplify it. Simplifying a fraction means expressing it in its simplest form, which may involve reducing it or canceling out common factors.

Q: Can I reduce a fraction that has a negative numerator or denominator?

A: Yes, you can reduce a fraction that has a negative numerator or denominator. The process is the same as reducing a fraction with positive numerators and denominators.

Q: How do I multiply fractions?

A: To multiply fractions, you simply multiply the numerators together and multiply the denominators together.

Q: Can I multiply a fraction by a whole number?

A: Yes, you can multiply a fraction by a whole number. To do this, you multiply the numerator of the fraction by the whole number and keep the denominator the same.

Q: How do I multiply a fraction by a decimal?

A: To multiply a fraction by a decimal, you can convert the decimal to a fraction and then multiply the fractions together.

Q: Can I multiply a fraction by a mixed number?

A: Yes, you can multiply a fraction by a mixed number. To do this, you convert the mixed number to an improper fraction and then multiply the fractions together.

Q: How do I divide fractions?

A: To divide fractions, you can invert the second fraction (i.e., flip the numerator and denominator) and then multiply the fractions together.

Q: Can I divide a fraction by a whole number?

A: Yes, you can divide a fraction by a whole number. To do this, you can invert the fraction and then multiply it by the whole number.

Q: How do I divide a fraction by a decimal?

A: To divide a fraction by a decimal, you can convert the decimal to a fraction and then divide the fractions together.

Q: Can I divide a fraction by a mixed number?

A: Yes, you can divide a fraction by a mixed number. To do this, you can invert the fraction and then multiply it by the mixed number.

Q: What are some common mistakes to avoid when working with fractions?

A: Some common mistakes to avoid when working with fractions include:

Not simplifying fractions to their lowest terms
Not inverting fractions when dividing
Not multiplying fractions correctly
Not converting decimals to fractions when necessary
Not converting mixed numbers to improper fractions when necessary

Q: How can I practice working with fractions?

A: You can practice working with fractions by:

Doing exercises and problems in a textbook or online resource
Using a calculator or computer program to practice calculations
Working with real-world examples, such as cooking or finance
Playing games or puzzles that involve fractions
Asking a teacher or tutor for help and practice