A decimal numeral system is a standard system that is used for denoting integer and non-integer numbers. Decimals consist of a whole number and a fractional part that is separated by a dot known as the decimal point. For example, 83.5 is a decimal number, where 83 is the whole number, and 5 is the fractional part. Decimals form an integral part of the number system and see use in topics such as percentages, fractions, and several other daily life applications. In this article, we will learn about the different methods that can be employed for multiplying decimals.
Multiplying decimals is similar to the multiplication of whole numbers. Below are the steps to follow while applying the multiplication operator to decimal numbers
- Multiply the given decimal numbers as you would multiply two or more whole numbers
- The total number of decimal places of the given numbers needs to be counted
- After multiplying the numbers, place the decimal point in the product in such a way that the number of decimal places in the product is equal to the sum of all decimal places in the given numbers
- A note to remember is that you must keep all the zeros in the product when you are placing the decimal point. After this placement, you can drop the zeros to the right of the decimal point. You can insert zeros in front of the product if the number of decimal places is greater than the number of digits in the product
Example: Multiply 42.3 and 5.39
- Multiply as whole numbers: 423 * 539 = 227997
- Count the total number of decimal places in the given numbers: 42.3 has one decimal place, and 5.39 has two decimal places. In total, we have three places
- Insert decimal point in the product: Counting three places from the left side, we get 227.997
- Thus, 42.3 * 5.39 = 227.997
Multiplying Decimals with Powers of 10
If you are multiplying a power of 10 such as 10, 100, etc., and a decimal number, you can count the number of zeros in the power of 10 and move the decimal point by those many numbers of places to the right.
Example: 0.0089 * 1000 = 8.9. As we can observe, the multiplier 1000 has three zeros, so the decimal point gets moved to the right by three places to give the product 8.9.
Multiplying Decimals with Whole Numbers
We multiply both numbers as whole numbers and get the product. The number of decimal places in the product will be equal to the number of places in the decimal number.
Example: Multiply 32.2 and 2
- 322 * 2 = 644
- As the number of decimal places in 32.2 is one; hence, our product will also have the same number of decimal places. Thus, 32.2 * 2 = 64.4
Decimals are very important for students as in daily life measurements, numbers usually occur in the form of decimals rather than whole numbers. The best way to study this chapter is by joining a good and reliable institution such as Cuemath. At Cuemath, the teachers focus on concept development and instilling kids with a robust mathematical foundation. They use resources such as interactive worksheets, online puzzles, math games apps, and visual simulations to deliver an impactful lecture and provide kids with a holistic learning environment. Hopefully, this article gives you an idea about how to multiply different decimals, and I wish you all the best in your learning journey.