Why round numbers

This is called rounding up. It sounds complicated but it isn't. Here are some examples. Let's review how to convert fractions to decimal. The 5 in 0.

This time you are trying to divide 10 by 3. Most of the time, you will use the rounded numbers 0. In fact, you usually work with just two or three digits to the right of the decimal point when there is no exact equivalent to the fraction in decimal. Remember to round up! What is the answer if you multiply 25 by 75?

You get Now multiply 0. You get 0. I'm counting the sheep in the pasture. Wolf 2: I invited all of them to a birthday party and I need to know how many pieces of cake I'll need. Wolf 1: But…how did you get sheep to come to a wolf 's party?

Wolf 2: I wore my wool sweater when I invited them! I'll round up to so I'll be sure to have enough cake. We suspected something was up, so we went to find the shepherd to make sure he knew about the wolf's party invitation.

The wolves' conversation got us to thinking about rounding numbers, though. Why exactly do we do that? If you've taken math classes for very long, then you've probably learned how to round numbers.

The most common method of rounding numbers goes as follows: first, decide which digit will be the last digit you keep also known as the digit you're rounding to. Then, look at the next digit and leave the last digit the same if the next digit is less than five round down or increase the last digit by one if the next digit is five or more round up. Finally, you replace the digits after the last digit with zero or leave them off completely if rounding a decimal. Let's look at Wendell the Wolf's example again to make it clear.

He counted sheep and he decided to round to the nearest hundred. So 1 was in the hundreds place and that's the last digit that will be kept. The next digit was 9, which is more than 5. So Wendell rounded up by adding 1 to the 1 and replacing the other digits with zeros to get What if Wendell had decided to round to the nearest ten?

He counted sheep, so 9 was in the tens place and that's the last digit that will be kept. The next digit was 2, which is less than 5. So Wendell would've rounded down by keeping the last digit the same and replacing the remaining digit with 0 to get Rounding numbers makes them simpler and easier to use. Although they're slightly less accurate, their values are still relatively close to what they originally were. People round numbers in many different situations, including many real-world situations you'll find yourself in on a regular basis.

Likewise, you may need an easy way to make simple calculations in your head to determine how many bags of candy you're able to buy at the store. How do you know that? Finally, it's often just easier to work with rounded numbers, because exact numbers aren't only required. If it takes about 25 minutes to get somewhere, it's simply easier to allow yourself 30 minutes of travel time. If you're talking about the population of New York City, it's easier to work with a figure of 8 million people rather than a more exact figure of 8,, people.

Are you ready to add, subtract, multiply, and divide? Don't forget to check out the following activities with a friend or family member:. We're sorry to hear that. Thanks for sticking with us! So glad to hear that! Hope you've been back since then to do some more wondering with us! We are talking about rounding numbers to to the nearest hundred and ten.

Some of my classmates include Madison and Stella. We are in third grade and my name is Emory. Hi, Emory! We really hope that this Wonder added to your discussion with your friends about why we round numbers! Do Madison and Stella know about Wonderopolis? We would love for them to be Wonder Friends, too!! Yep - have have a Wonder about that!

Wonder What's the Science of Glass Blowing? Hi, yesenia! We're thrilled that you read this Wonder! Always remember to first identify which numbers you'll be considering when rounding the place value. Then, use the rule of rounding up and down to determine what the final number will be. Back to Course Index. You can still navigate around the site and check out our free content, but some functionality, such as sign up, will not work. If you do have javascript enabled there may have been a loading error; try refreshing your browser.

Home Basic Math Numbers and Relations. Still Confused? Nope, got it. Play next lesson. Try reviewing these fundamentals first Place value Comparing and ordering numbers. That's the last lesson Go to next topic.

Still don't get it? Review these basic concepts… Place value Comparing and ordering numbers Nope, I got it. Play next lesson or Practice this topic. Play next lesson Practice this topic. Start now and get better math marks! Intro Lesson: a. Lesson: 1a. Lesson: 1b. Lesson: 2a. Lesson: 2b. Lesson: 2c. Lesson: 3a. Lesson: 3b. Lesson: 3c. Lesson: 4a.