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Last updated on May 26th, 2025

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15/21 as a Decimal

Professor Greenline Explaining Math Concepts

It is a simple question on decimal conversion. Firstly, we have to understand fractions and decimals. A fraction represents a part of a whole. It has two parts: the numerator (the number on the top), here, 15, which indicates how many parts out of the whole. The denominator (the number below) shows how many parts make up the whole, here it is 21. A decimal is a way to represent a number that is not whole, using a (.) or a decimal point to separate the whole part from the fractional part. The numbers to the left of the decimal point represent the whole, and those to the right represent the fractional part.

15/21 as a Decimal for Indonesian Students
Professor Greenline from BrightChamps

What is 15/21 as a decimal?

15/21 as a decimal

Answer

 

15/21 in decimals can be simplified and then written as approximately 0.71428. This is not a recurring decimal as it eventually terminates.

 

Explanation

 

To convert 15/21 into a decimal, we first simplify the fraction and then use division. Let's see the step-by-step breakdown of the process:

 

Step 1: Simplify the fraction. Both 15 and 21 can be divided by their greatest common divisor, which is 3. So, 15/21 simplifies to 5/7.

 

Step 2: Identify the simplified numerator and denominator because the numerator (5) will be taken as the dividend and the denominator (7) will be taken as the divisor.

 

Step 3: Divide 5 by 7 using long division. As 5 is smaller than 7, we add a decimal point and a 0 to make it 50.

 

Step 4: Determine how many times 7 fits into 50, which is 7 times (7 x 7 = 49). Write 7 in the quotient place and subtract 49 from 50 to get 1.

 

Step 5: Bring down another 0, making it 10, and repeat the division process.

 

Step 6: Continue the process until you get a remainder of 0 or decide to stop at a certain decimal place.

 

The answer for 15/21 as a decimal is approximately 0.71428.

Professor Greenline from BrightChamps

Important Glossaries for 15/21 as a decimal

  • Fraction: A numerical quantity that is not a whole number, representing a part of a whole.

 

  • Decimal: A number that uses base ten and includes a decimal point to separate the whole part from the fractional part.

 

  • Numerator: The top part of a fraction, indicating how many parts of the whole are being considered.

 

  • Denominator: The bottom part of a fraction, showing how many parts make up a whole.

 

  • Simplification: The process of reducing a fraction to its simplest form by dividing both the numerator and the denominator by their greatest common divisor.
Professor Greenline from BrightChamps

About BrightChamps in Indonesia

At BrightChamps, math questions are more than simple exercises—they open up countless possibilities! Our mission is to support kids across Indonesia in developing key skills like today’s focus on the 15/21 as a Decimal, with particular attention on decimal conversions—in a fun, engaging, and easy-to-understand way. Whether your child is figuring out the speed of a roller coaster at Dunia Fantasi, keeping score in a local badminton game, or managing their allowance to buy gadgets, mastering math builds their confidence to tackle daily challenges. Our interactive lessons make learning both fun and easy. Since children in Indonesia learn differently, we tailor our approach to meet their individual styles. From the lively streets of Jakarta to the gorgeous beaches of Bali, BrightChamps makes math relevant and exciting throughout Indonesia. Let’s make decimal conversions a fun part of every child’s learning journey!
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