One of the strategies emphasized in elementary math classes is the ability to round numbers. In rounding, numbers are changed to a number that is either larger or smaller depending on which it is closer too. Because rounding numbers can seem abstract (especially as the numbers get larger), it can be a difficult task for students to master.
There are several ways to teach rounding to children. Each child learns differently, so your child may benefit from one strategy over another. If you already know how your child learns, you can use the practice that you know will work. However, if you are not sure how your child best learns, feel free to try out all the strategies!
Rounding on a Number Line
This strategy is especially good for students who are visual learners or who still struggle with abstract concepts.
- Draw a number line that starts at the first rounding choice, ends at the second rounding choice, and includes the number you are rounding. (For example: If your child is rounding 84 to the tens place, draw a number line starting at 80 and ending at 90 including all the numbers in between.)
- Have your child color a dot on the number that he is rounding. Using a colored pencil or crayon will make this even more fun.
- Then your child decides which end of the number line his number is closest too. This will be the rounded answer. (In our example, 84 is closer to 80, so 80 is the correct answer.)
Rounding with a Rule
Some students work better with a rule that they can follow for every problem. This strategy allows them to follow the same procedure for any number they need to round. Write the following rule on a note card or paper and encourage them to use it for some rounding examples to make sure they understand it.
- Underline the place you are rounding to. Let’s round 873 to the hundred’s place this time. In this example, underline the 8 in the hundred’s place.
- Draw an arrow under the place to the right of the underlined number. We would draw an arrow under the 7.
- Use the arrow place to make a decision about the underlined place. Here is the rule to follow: 4 and below – the number stays the same; 5 and above – the number adds one. “We Will Round You” is a cute Youtube song to help children remember this rule.
- Change the number in the underlined place to fit the rule. Because the 7 is above 5, we add one to the 8 making it 9.
- The numbers to the right all become 0’s. Any numbers to the left of the place stay the same. So we end up with 900 as the rounded answer for our example.
Rounding can be easy for children with some simple strategies and lots of review.
How do you help your children master rounding numbers?