how do you write 1 1/2 as a decimal

2 min read 01-03-2025

The mixed number 1 1/2 represents one whole unit plus one-half of a unit. To convert this to a decimal, we need to understand that the decimal system is based on powers of 10. Let's break down the process step-by-step.

Understanding Fractions and Decimals

Before we convert 1 1/2, let's quickly review the relationship between fractions and decimals. A fraction represents a part of a whole. A decimal also represents a part of a whole, but it uses a base-ten system. The numbers to the right of the decimal point represent tenths, hundredths, thousandths, and so on.

Converting 1 1/2 to a Decimal: The Methods

There are two main ways to convert 1 1/2 to a decimal:

Method 1: Converting the Fraction to a Decimal

Convert the fraction to a decimal: The fraction 1/2 is equivalent to 0.5 (one divided by two). You can perform this division using a calculator or long division.
Add the whole number: Add the whole number part (1) to the decimal equivalent of the fraction (0.5): 1 + 0.5 = 1.5

Therefore, 1 1/2 as a decimal is 1.5.

Method 2: Converting to an Improper Fraction First

Convert to an improper fraction: To convert the mixed number 1 1/2 to an improper fraction, multiply the whole number (1) by the denominator (2) and add the numerator (1). This gives you 3. Keep the same denominator (2). So, 1 1/2 becomes 3/2.
Divide the numerator by the denominator: Divide the numerator (3) by the denominator (2): 3 ÷ 2 = 1.5

Again, we find that 1 1/2 as a decimal is 1.5.

Why This Matters

Understanding how to convert fractions to decimals is a fundamental skill in math. It's crucial for various applications, including:

Measurement: Many measurements use decimal notation (e.g., 1.5 meters).
Calculations: Decimals are often easier to work with in calculations than fractions.
Data analysis: Data is frequently represented using decimal numbers.

Conclusion

Converting 1 1/2 to a decimal is straightforward. Whether you convert the fraction to a decimal first or convert to an improper fraction, the result is always the same: 1.5. This simple conversion highlights the interchangeable nature of fractions and decimals in representing parts of a whole. Mastering this conversion is a valuable tool for many mathematical applications.