A decimal number is a number that consists of a whole number and a fractional part. Decimal numbers lie between integers and represent numerical values for quantities that are whole plus some part of a whole (SplashLearn, n.d.).
Key Facts
- Decimal numbers represent values that are whole plus some part of a whole.
- The decimal point is represented by a dot, and it separates the whole part from the fractional part.
- The place value system for decimals is similar to the place value system for whole numbers. However, as we move to the right of the decimal point, each place value is 1/10 times smaller than the value to its left.
- The first place after the decimal point is called “tenths” and represents a value of 1/10 of the whole. The second place is called “hundredths” and represents a value of 1/100 of the whole. The third place is called “thousandths” and represents a value of 1/1000 of the whole.
- Decimals can be used in various real-life situations, such as in monetary transactions, measurements, and sports scores.
- Decimals can be compared, added, subtracted, multiplied, and divided, just like whole numbers.
- Decimals can be written as fractions. For example, 0.5 is the same as 1/2, and 0.25 is the same as 1/4.
- Decimals can be rounded to a certain place value. For example, rounding 3.78 to the nearest tenth would give 3.8.
Understanding Decimals
Decimal Point:
The decimal point is a dot that separates the whole part of a decimal number from the fractional part (Twinkl, n.d.).
Place Value System:
The place value system for decimals is similar to the place value system for whole numbers. However, as we move to the right of the decimal point, each place value is 1/10 times smaller than the value to its left (Twinkl, n.d.).
Decimal Places:
The first place after the decimal point is called “tenths” and represents a value of 1/10 of the whole. The second place is called “hundredths” and represents a value of 1/100 of the whole. The third place is called “thousandths” and represents a value of 1/1000 of the whole (Twinkl, n.d.).
Applications of Decimals
Decimals are used in various real-life situations, including:
- Monetary transactions: A dollar is made up of 100 cents, and the prices of objects are written in decimals, such as USD 2.79 (TheSchoolRun, n.d.).
- Measurements: Decimals are used to measure quantities such as length, weight, and volume. For example, a length of 3.5 meters or a weight of 2.7 kilograms (Twinkl, n.d.).
- Sports scores: Decimals are used to represent scores in sports such as baseball and cricket (Twinkl, n.d.).
Operations with Decimals
Decimals can be compared, added, subtracted, multiplied, and divided, just like whole numbers (Twinkl, n.d.).
Decimals and Fractions
Decimals can be written as fractions. For example, 0.5 is the same as 1/2, and 0.25 is the same as 1/4 (Twinkl, n.d.).
Rounding Decimals
Decimals can be rounded to a certain place value. For example, rounding 3.78 to the nearest tenth would give 3.8 (Twinkl, n.d.).
Conclusion
Decimals are a fundamental part of our number system and are used in various real-life applications. Understanding decimals is essential for students to develop their mathematical skills and solve problems involving fractional quantities.
References
- SplashLearn. (n.d.). Decimal – Definition, Types, FAQs, Examples. Retrieved from https://www.splashlearn.com/math-vocabulary/decimals/decimal
- Twinkl. (n.d.). Decimal. Retrieved from https://www.twinkl.co.uk/teaching-wiki/decimal
- TheSchoolRun. (n.d.). What are decimals? Retrieved from https://www.theschoolrun.com/what-are-decimals
FAQs
What is a decimal?
A decimal is a number that consists of a whole number and a fractional part, separated by a decimal point.
How do you read a decimal?
Read the whole number part as you would read any whole number, then read the decimal point as “point,” and then read each digit of the fractional part individually.
What is the place value of the digits in a decimal number?
The place value of the digits in a decimal number follows the same rules as the place value of digits in whole numbers. However, as you move to the right of the decimal point, each place value is 1/10 times smaller than the value to its left.
How do you compare decimals?
To compare decimals, line them up vertically, starting at the decimal point. Then, compare the digits in each place value column, starting from the left. The decimal with the greater digit in the first non-zero place value column is the greater number.
How do you add and subtract decimals?
To add or subtract decimals, line them up vertically, starting at the decimal point. Then, add or subtract the digits in each place value column, starting from the right. Bring down the decimal point in the answer.
How do you multiply decimals?
To multiply decimals, multiply the numbers as if they were whole numbers, ignoring the decimal points. Then, count the total number of decimal places in the two factors and place the decimal point in the product accordingly.
How do you divide decimals?
To divide decimals, first rewrite the division problem as a fraction, with the dividend as the numerator and the divisor as the denominator. Then, multiply both the numerator and denominator by a power of 10 that makes the denominator a whole number. Finally, divide the numerator by the denominator as you would divide whole numbers.
How are decimals used in real life?
Decimals are used in various real-life situations, including monetary transactions, measurements, and sports scores. For example, a dollar is made up of 100 cents, and the prices of objects are written in decimals, such as USD 2.79. Decimals are also used to measure quantities such as length, weight, and volume, and to represent scores in sports such as baseball and cricket.