3 Ways to Subtract Fractions
Introduction
Subtracting fractions is an essential skill in mathematics that allows us to solve problems involving fractions. In this article, we will explore three different methods for subtracting fractions: (1) with common denominators, (2) using a least common denominator, and (3) converting to decimals. By mastering these techniques, you’ll become a whiz at handling any fraction subtraction problem that comes your way.
1. Subtracting Fractions with Common Denominators:
The easiest way to subtract fractions is when the denominators are already the same. In this case, you simply subtract the numerators and leave the denominators unchanged. For example:
5/6 – 3/6 = (5 – 3)/6 = 2/6 = 1/3
Here, both fractions have the denominator of 6. We subtracted the numerators and then simplified the result.
2. Subtracting Fractions using a Least Common Denominator (LCD)
When dealing with fractions that have different denominators, you must first find their least common denominator (LCD). The LCD is the smallest multiple both denominators share. Once you find it, convert each fraction to an equivalent fraction with the LCD as its denominator before performing subtraction. Let’s break it down into steps:
Step 1: Find the LCD
Step 2: Convert each fraction to its equivalent fraction with the LCD
Step 3: Subtract the fractions now that they have the same denominator
Example:
2/3 – 1/4
Step 1: The LCD for denominators 3 and 4 is 12.
Step 2: Convert each fraction:
(2/3) x (4/4) = 8/12
(1/4) x (3/3) = 3/12
Step 3: Subtract the converted fractions:
8/12 – 3/12 = (8 – 3)/12 = 5/12
Thus, the answer is 5/12.
3. Subtracting Fractions by Converting to Decimals:
Sometimes, it might be easier to convert your fractions into decimals and then subtract them. To convert a fraction to a decimal, divide the numerator by the denominator. Once you have converted both fractions into decimals, simply subtract the decimal values. The following example demonstrates this method:
Example:
3/5 – 1/4
Step 1: Convert each fraction to its decimal equivalent:
(3 ÷ 5) = 0.6
(1 ÷ 4) = 0.25
Step 2: Subtract the decimal values:
0.6 – 0.25 = 0.35
Thus, the answer is approximately 0.35.
Conclusion:
Mastering subtraction of fractions can be accomplished using any of these three methods: with common denominators, using an LCD, or converting to decimals. Make sure to practice each technique so that you can confidently tackle fraction subtraction problems in any situation!