Rounding Whole Numbers

17 teachers like this lesson
Print Lesson

Objective

Students will be able to show how to use place value to round whole numbers.

Big Idea

You can round numbers by using place value.

Opener

5 minutes

In the Video on Rounding Whole Numbers, I explain our lesson for today.

In today's lesson, the students learn to round whole numbers.  This aligns with 4.NBT.A3 because the students use place value understanding to round multi-digit whole numbers to any place.

I remind the students that they have used place value to read numbers.  I say, "Today, you will learn to use place value to round numbers.  Sometimes, we do not need the exact number, we need to find an estimate, which is a number close to the exact number.  When might you need to use a number that is an estimate?"  I give the students a few minutes to think about the question.  I call on a few students to respond.  Student responses: 1) when we count things in a jar and 2) when we figure out how much notebook paper we have left in our folder.

Direct Instruction

10 minutes

I allow the students to come to the carpet for the whole class discussion on rounding whole numbers.  I use the  Rounding Whole Numbers power point to teach the lesson.  I let the students know that rounding is a very important skill in their every day lives.  If the students know that a skill will benefit them, they are more attentive to the lesson.

I tell the students that when you round, you can use place value to help you.  A number line is another tool that can be used to help you round.
On the Smart board, I show the following scenario:

There are 5,278 people at the amusement park.  About how many people are there, rounded to the nearest thousands place?  Let’s find out.

—What number is in the thousands place?

    (5 is in the thousand place)

 Â—What number is to the right of the 5?

    (2 is to the right of 5)

Let’s review the rules of rounding.

Rules of Rounding:

—If the number to the right is 5 or more (5, 6, 7, 8, or 9), the underlined digit goes up by one.  All numbers behind the underlined place are changed to zeros. (It rounds up.)

—If the number to the right is 4 or less (4, 3, 2, 1, or 0), the underlined digit stays the same and all numbers behind it becomes zeros. (It rounds down.)

There is a 2 in the hundreds place, therefore, the 5 stays the same.  All numbers behind it becomes zeros.

5,278 rounds to 5,000

This means that 5,278 is closer to 5,000 than 6,000.

Let’s see what this means on a number line.

I show the slide with the number line.  I tell the students that I want to round 5,278 to the nearest thousands.

By placing the number on the number line, you can see that 5,278 is closer to 5,000 than 6,000.

 

 


 

 

Group Activity

20 minutes

I put the students in groups of 3.  Each group gets a Rounding Numbers and Directions sheet and Rounding Score Sheet.  Each student has a role.  There is a dealer, player, and scorer.  The dealer turns over 4 numbers and 1 rounding direction card.  The player must round the number to the place identified by the rounding direction card.  The player has 1 minute to round the number or they lose their turn.  The scorer checks the student's work and rewards them with a point if they are correct.  The roles change going clockwise to allow all students a chance to round numbers.  The students repeat the process until time is up.

As the students participate in the activity, I walk around to monitor.  By their eagerness, it is evident that the students really enjoy this activity.  They are focused on getting their answers right because they want to win!  As I monitor, I listen in on the students conversation.  Math practice 3 is very important in my classroom.  If the answer is wrong, I want to hear the scorer catching the mistake.  In several situations, I listened in as the player defended their answers.  The environment is kid friendly and Common Core focused.

 

 Early Finishers:  Any students finishing the activity early can practice the skill at the following site:  http://www.mathnook.com/math/match-around.html

 

 

Note to Teachers:  This activity can be done with a deck of cards (remove the cards that are 10 and above) or with a number cube.

 

 

Independent Activity/Exit Ticket

10 minutes

Group activities are great, but independent activities are necessary.  As a teacher, I like to know how each of my students are doing individually.  Giving an independent activity/Exit Ticket is a great way to assess the students.

I give each student a Exit Ticket Rounding Whole Numbers.

The assignment reads as follows:

There were 8,547 people traveling to Disney World for summer vacation.  About how many people were traveling to Disney World rounded to the nearest hundreds?  Explain how the rules of rounding helped you find your answer.

Upon completion of the exit ticket, I collect them for evaluation.  Any student having difficulty with the skill will be pulled for small group instruction.