# Decimals: Introduction to Decimals

### What are decimals?

A decimal is another way to write a fraction. You can think of a decimal as a part of a whole number. It is less than 1 whole thing, but more than 0.

You may not realize it, but you see decimals a lot in real life. One of the most common examples is money. Do you recognize these coins? We have a quarter, a dime, and two pennies. You could write each of these as a decimal. That's because each coin is worth less than a whole dollar.

Click through the slideshow to learn how decimals work.

• This is a dollar. A dollar represents a whole number. It is equal to 1.

• We could also write that as 1.00. In other words, 1 = 1.00.

• 1.00 is a decimal. Here, it means we have 1 dollar and 0 cents.

• As you may already know, there are 100 pennies in a dollar. This means 100 pennies equals 1.00.

• One penny is part of a dollar. More specifically, it's 1 cent. We could also write that as a decimal: 0.01.

• Let's look at a few more decimals. 9 cents is 0.09 of a dollar.

• A quarter, or 25 cents, is 0.25 of a dollar. Any time you have part of a whole, you can write it as a decimal.

• Let's look at another example. This pitcher holds 1 liter of water. Right now it's full.

• We could write this as a decimal: 1.00 liters.

• The pitcher is split into 10 parts. This means each part is equal to 0.10 liters.

• As the day goes on, the pitcher gets emptier. Now it has 0.70 liters. That's because we used up 0.30 liters.

• Now it has 0.50 liters, or half a liter.

• Now it has 0.20 liters. Even though we have less than one liter, we have more than zero liters, so we can write it as a decimal.

• As you saw on the last page, decimals look a lot like a regular numbers, with a few important differences. First, all decimals have a decimal point (.). The decimal point looks like a period. Any number to the left of the decimal point is a whole number. The numbers to the right are like a fraction—they're less than 1 whole but more than 0.

For example, let's take a look at this decimal.

9.6

9 is on the left of the decimal point, so we have 9 whole things. 6 is on the right, so we also have 6 parts of a whole.

We see written decimals all the time in real life. For example, you might know that the average body temperature is 98.6 degrees. Or you might tune in to a radio station like 97.5. But do you know how to read these decimals out loud?

Click through the slideshow to learn how to read decimals.

• Let's try reading this decimal: 9.6.

• First, we'll read the number to the left of the decimal point. That's nine.

• Next, we'll read the decimal point. Usually, you'll just say "point".

• Finally, we'll read any number to the right of the decimal point. That's six.

• So, we'd read 9.6 like this: nine point six.

• But you could also read it like this: nine and six-tenths.

• When you read decimal numbers, each place to the right of the decimal point has a special name.

• The place immediately to the right of the decimal point is the tenths place.

• Here, the decimal means we have .6, or six-tenths, of a whole.

• You might remember from Introduction to Fractions that six-tenths is just another way of saying 6/10.

• So 9.6 means we have 9 whole things and 6/10, or six-tenths, of another thing.

• Since we have nine and six-tenths, the word "and" replaces the decimal point.

• Let's try another example. How would you read this decimal? 0.25.

• We can read 0.25 as zero point two five...

• We can read 0.25 as zero point two five...or leave out the zero and just say point two five.

• But we could also read it like this: twenty five-hundredths.

• Let's look at our decimal places again. 2 is in the tenths place, so we have two-tenths.

• Next is the hundredths place. In this example, 5 is in the hundredths place, so we have five-hundredths.

• When we read this number aloud, we'll say the 2 and 5 together as "twenty-five".

• We'll also say the decimal place that is farthest to the right. In our example, that's the hundredths place.

• So we'll read 0.25 as twenty five-hundredths.

• This is just another way of writing 25/100.

• To figure out how many hundredths we had total, we could have added these numbers: two-tenths and five-hundredths.

• 2 tenths is the same as 0.20, or twenty-hundredths.

• 0.20 plus 0.05 equals 0.25, or twenty five-hundredths.

• #### Try This!

Try reading the decimals below aloud. ### Decimals and money Even though we use decimals when we use money, we read them slightly differently. Instead of three point two three, or three and twenty three-hundredths, we'll say three dollars and twenty-three cents.

You could also read it like this: "three twenty three". To save time, most people leave out the decimal point when talking about money. How about \$5.99? That would be five dollars and ninety-nine cents, or five ninety-nine.

Remember, these rules only work with money. They can't be used to read other decimals.

#### Try This! ### Comparing decimals

Let's imagine you're shopping for a new water pitcher. You find two you like—one holds 0.7 gallons, while the other holds 0.5 gallons. Do you know which pitcher is larger? Click the arrows to find out.

• To find out which pitcher holds more, you could simply compare the decimals to see which is larger.

• 7 is larger than 5, so 0.7 is larger than 0.5. The larger the number to the right of the decimal point, the larger the decimal.

#### How about these two decimals:

• Again, you'll simply compare the numbers to the right of the decimal point.

• 74 is larger than 72, so 0.74 is larger than 0.72.

#### Now let's compare these decimals:

• Since the whole number, 1, is the same for both decimals, we'll compare the numbers to the right of the decimal point.

• If you thought .2 was larger than than .19, you were right!

• Remember, 1.2 could also be written as 1.20.
20 is larger than 19, so 1.20 is larger than 1.19.