Calculating Leftover Ribbon Length: A Step-by-Step Guide

When working with ribbon lengths, it's important to ensure that all measurements are consistent and accurate. In this article, we'll go through the process of calculating the remaining length of a roll of ribbon after some has been used for party decoration. We'll use millimeters (mm) for all measurements and provide a detailed, step-by-step solution. This guide is suitable for SEO optimization and follows Google's best practices for content.

Problem Statement

A roll of ribbon is 20 1/2 cm in length. 15 1/5 cm is used to make decoration for the party. How much ribbon is left?

Solution

Step 1: Convert to Millimeters

First, let's convert the given measurements to millimeters (mm). We know that 1 cm 10 mm. Therefore:

20 1/2 cm 20.5 cm 205 mm 15 1/5 cm 15.2 cm 152 mm

Now, we can use these values to calculate the remainder.

Step 2: Perform the Subtraction

To find the remaining length, we subtract the used length from the original length:

205 mm - 152 mm 53 mm

Alternative Method

Alternatively, we can keep the problem in cm to make it easier to understand. Let's convert back to centimeters and perform the calculation:

20 1/2 cm - 15 1/5 cm ?

Step 3: Convert Fractions to a Common Denominator

Now, we need to convert the fractions to a common denominator to perform the subtraction. The denominators are 2 and 5. The least common denominator (LCD) is 10.

20 1/2 cm 20 1/2 20 5/10 15 1/5 cm 15 1/5 15 2/10

Now, we can subtract the fractions:

20 5/10 - (15 2/10) 20 5/10 - 15 - 2/10

Since the whole numbers (20 and 15) easily subtract:

20 - 15 5

Now, subtract the fractions:

5/10 - 2/10 3/10

So, the remaining length is:

5 3/10 cm

Step 4: Convert to Decimal Form

For a more precise and commonly used format, we can convert the fraction to a decimal:

3/10 0.3

Therefore, the remaining length in centimeters is:

5.3 cm

Conclusion

In summary, the remaining length of the ribbon is 53 mm or 5.3 cm. This method ensures accuracy and consistency in measurements, which is crucial for tasks involving materials like ribbons for decorative purposes.

If you have any questions or need further assistance with similar problems, feel free to reach out. Happy crafting!