Cara Membaca Bilangan Desimal

>Hello Sohib EditorOnline, we all have had to deal with decimals at some point in our lives – whether it’s counting money or calculating percentages, decimals are an essential part of math. In this article, we will guide you through the process of reading and understanding decimal numbers. Let’s get started!

What Are Decimal Numbers?

Decimal numbers are a way of representing parts of a whole using a base-10 system. This means that each digit in a decimal number represents a power of 10, starting from the leftmost digit. For example, in the number 123.45, the digit 1 represents 100, the digit 2 represents 10, and the digit 3 represents 1. The digits after the decimal point represent smaller fractions of a whole.

To read a decimal number, we simply say the digit followed by its corresponding power of 10. For example, to read the number 123.45, we say “one hundred and twenty-three point four five”. Let’s look at some more examples:

Example 1:

Decimal Number	Read as
0.25	zero point two five
1.5	one point five
10.75	ten point seven five

Example 2:

Decimal Number	Read as
0.001	zero point zero zero one
2.35	two point three five
100.9	one hundred point nine

How to Add and Subtract Decimal Numbers

Adding and subtracting decimal numbers is similar to adding and subtracting whole numbers. The key is to line up the decimal points vertically and then carry out the operation as usual.

Let’s take the following example:

Example 3:

5.6 + 2.47 = ?

To solve this problem, we line up the decimal points:

5.6
+	2.47
—-

Now we can add the numbers as usual:

5.6
+	2.47
—-
8.07

Therefore, 5.6 + 2.47 = 8.07.

Subtraction works in the same way. Let’s take the following example:

Example 4:

10.5 – 3.2 = ?

To solve this problem, we line up the decimal points:

10.5
–	3.2
—-

Now we can subtract the numbers as usual:

10.5
–	3.2
—-
7.3

Therefore, 10.5 – 3.2 = 7.3.

How to Multiply and Divide Decimal Numbers

Multiplying and dividing decimal numbers is similar to multiplying and dividing whole numbers. The key is to ignore the decimal point and treat the numbers as if they were whole numbers. After carrying out the operation, we need to count the number of decimal places in the numbers being multiplied or divided and place the decimal point in the result accordingly.

Let’s take the following example:

Example 5:

2.5 x 1.2 = ?

To solve this problem, we ignore the decimal points and treat the numbers as if they were whole numbers:

25
x	12
—-

Now we can multiply the numbers as usual:

25
x	12
—-
300

There are 1 + 1 = 2 decimal places in the numbers being multiplied, so we place the decimal point in the result two places from the right:

2.5 x 1.2 = 3.00.

Division works in the same way. Let’s take the following example:

Example 6:

8.4 / 2.1 = ?

We ignore the decimal points and treat the numbers as if they were whole numbers:

84
/	21
—-

Now we can divide the numbers as usual:

84
/	21
—-
4

There are 1 + 1 = 2 decimal places in the numbers being divided, so we place the decimal point in the result two places from the right:

8.4 / 2.1 = 4.00.

FAQ

Q: Can decimals be negative?

A: Yes, decimals can be negative. A negative decimal is represented by a minus sign (-) before the decimal point.

Q: How do I convert a decimal to a percentage?

A: To convert a decimal to a percentage, multiply by 100 and add the percent sign (%). For example, 0.25 = 25%.

Q: How do I convert a percentage to a decimal?

A: To convert a percentage to a decimal, divide by 100. For example, 50% = 0.5.

Q: How do I round a decimal?

A: To round a decimal to a certain number of decimal places, look at the digit in the next decimal place. If it is 5 or greater, round up. If it is less than 5, round down. For example, to round 1.234 to two decimal places, we look at the digit in the third decimal place (4). Since 4 is less than 5, we round down to get 1.23.

Q: How precise do decimal calculations need to be?

A: The precision of decimal calculations depends on the context in which they are being used. For example, counting money requires a high level of precision, while estimating the length of a piece of wood may require less precision.

That’s all for this article on cara membaca bilangan desimal. We hope that this guide has been helpful in understanding and working with decimal numbers. Happy calculating!

Cara Membaca Bilangan Desimal