Rounding Whole Numbers

Rounding whole numbers plays a crucial role in a child’s mathematical development as it serves as one of the fundamental tools used to grasp more complex concepts. Rounding whole numbers is very useful as it helps simplify problems so students can estimate answers. Having a general idea of what an equation’s answer should be provides kids with the confidence to approach an equation that may otherwise seem too difficult.

The first step to rounding whole numbers is knowing whether a number rounds up or down. Essentially, your student is determining the closest number (be it ten, hundred, thousand, or greater) a given integer rounds up or down to. Thus, one important rule is that if the number in question is less than 5, it rounds down. Conversely, if the number is 5 or bigger, it rounds up. Look at the following examples and have your child round them to the nearest ten. Since we are using ones, the integer will either round to 0 or 10.

Using the rule mentioned above, your student should have come up with these answers:

Next, let’s try rounding whole numbers with more digits. When rounding whole numbers with multiple integers, kids must understand the concept of place value. For this introductory lesson, let’s focus on place values ranging from ones to thousands. In the number below, have your student identify what number is in the ones, tens, hundreds, and thousands values.

Now that your child can identify place value, have them practice rounding whole numbers using 3,429. First, what is 3,429 rounded to the nearest ten?

Since we want to know what 3,429 is rounded to the nearest ten, we must look at two numbers: the 2 in the tens place and the 9 in the ones place. Since we are rounding to the nearest ten, we must determine if 29 is closer to 20 or 30. Thus, the tens value will remain a 2 if it rounds down or become a 3 if it rounds up. To decide if the number rounds up or down, look at the ones place value. Is 9 greater than or less than 5? Since 3,429 has 9 ones, we determine that it rounds up to 30.

Let’s move on rounding to the nearest hundred. Using a similar approach, look at the numbers in the hundreds and tens place: 4 and 2.

Since we are rounding to the nearest hundred, we want to know if 429 rounds down to 400 or up to 500. Looking at the 2 in the tens place will determine what the answer is. Is 2 greater than or less than 5? Since it is less than 5 we know that 429 rounds down to 400.

One last problem, this time rounding to the nearest thousand. Look at the numbers in the thousands and hundreds values to solve this problem.

Using the 4 in the hundreds place to determine if we round up or down to the nearest thousand, use the same process as in the previous questions. Is 4 greater than or less than 5? Knowing that 4 is less than 5, we determine that 3,429 rounds down to 3,000.

Rounding whole numbers may take a little practice to master, but once your children understand the reasoning behind this concept, they will be able to solve various problems with ease. As we have seen in the given examples, place value is important to know when rounding whole numbers. Even when practicing with place value worksheets, encourage your kids to round the numbers to test their rounding skills as well.