How to Teach Rounding
Count by ones to 10., Count by tens to 100., Count by hundreds to 1,000., Continue to practice skip counting other groups of numbers., Write a four-digit number., Review the ones place., Review the tens place., Review the hundreds place., Review the...
Step-by-Step Guide
-
Step 1: Count by ones to 10.
If students needs help, they can use their fingers or manipulatives.
Before learning to round, students must be able to skip count.
Skip counting allows students to identify the nearest ten or nearest hundred to a number that is being rounded.
Students also need to understand the difference between counting by ones, tens, and hundreds, to activate their understanding of place value. -
Step 2: Count by tens to 100.
Choose random tens, and ask the students which ten is above it.
Students can use a hundreds chart if need be.
For example, after the students can count by tens to 100, ask, “What ten is above 20? 30 is the ten above
20.” , Choose random hundreds, and ask the students which hundred is above it.
Students can use a thousands chart if need be.
For example, after the students can count by hundreds to 1,000, ask, “What hundred is above 400? 500 is above
400.” , The skip counting you do will depend on the type of rounding you expect the students to do.
For example, if rounding to the ten thousands place, practice skip counting by thousands and ten thousands. , Choose a number that has different digits in each place value, for clarity’s sake.
It is essential that students have a complete understanding of place value before attempting to teach them rounding.
If students have already mastered place value, you can skip this part.
This assumes you are teaching rounding to the tens or hundreds.
If you are teaching rounding to the thousands or more, you might want to write a number that has 5 or more digits.
For example, you might write the number 3,892. , Point to the digit farthest to the right.
Explain the value of the digit in the ones place.
Count by ones until you reach the value.
You can use base 10 blocks or other manipulatives to help illustrate the value of each digit.
For example, in the number 3,892, point to the 2 and explain that the 2 is in the ones place, and the value of 2 twos is
2.
Count: “1,
2.” , Point to the digit second from the right.
Explain the value of the digit in the tens place.
Count by tens until you reach the value.
For example, in the number 3,892, point to the 9 and explain that the 9 is in the tens place, and the value of 9 tens is
90.
Count: “10, 20, 30, 40, 50, 60, 70, 80,
90.” , Point to the digit third from the right.
Explain the value of the digit in the hundreds place.
Count by hundreds until you reach the value.
For example, in the number 3,892, point to the 8 and explain that the 8 is in the hundreds place, and the value of 8 hundreds is
800.
Count: “100, 200, 300, 400, 500, 600, 700,
800.” , Point to the digit fourth from the right.
Explain the value of the digit in the thousands place.
Count by thousands until you reach the value.
For example, in the number 3,892, point to the 3 and explain that the 3 is in the thousands place, and the value of 3 thousands is 3,000.
Count: “1,000, 2,000, 3,000.” , Rounding is changing a difficult number to a number close by.
We round a number to make it easier to use.For example, if you are trying to figure out about how many total cookies you and your friend ate last year, and you ate 327 cookies while your friend ate 286, you could round both numbers to 300, because 300 + 300 is easier to calculate than 327 +
286. , We often round to the nearest ten, hundred, or thousand.
Review what place value the students are rounding to.
For example, you might want student to round to the nearest hundred.
Review where the hundreds place is, if necessary. , The number should go to at least the same place value students are rounding to.
For example, if students are rounding to the nearest hundred, you might choose the number
892. , Determine the value, and ask for the rounded number above it.
For example, if rounding 892 to the nearest hundred, students should locate the 8, and understand that its value is
800.
Ask, “What hundred is above 800? 900 is above
800.” Emphasize that students are rounding to the nearest hundred. , The number on the far left of the line should be the value of the digit in the target place value.
The value on the far right should be the rounded number above it.
Use hash marks to skip count up the number line.
For better accuracy, it is helpful to use preprinted number lines instead of hand-drawn number lines.
For example, if rounding 892 to the nearest hundred, the number on the far left of the number line would be 800, and the number on the far right of the number line would be
900.
In between, the hash marks would skip count by tens: 810, 820, 830, 840, 850, 860, 870, 880, 890,
900. , Mark this point on the line.
You can mark the point with a star or dot, or you can trace over the first half of the number line in one color, and trace the second half of the number line in another color.
For example, if using a number line that begins with 800 and ends with 900, the halfway point would be 850, so you would draw a star on the 850 hash mark. , Use the additional hash marks on the number line to denote other place values as necessary.
Draw a dot on the appropriate hash mark, and write the number above the dot.
For example, if plotting 892, you would draw nine hash marks between 890 and 900, and draw a dot on the second hash mark after
890. , Determine whether the number is closer to the first number on the number line, or the last number on the number line.
For example, ask students if 892 is above or below
850.
Since it is above 850, it is closer to 900 than it is to
800. , Whether we round up or down depends on which rounded number our actual number is closest to.
If the actual number is closer to the lower rounded number, or below the halfway point, we round down.
If the number is exactly at the halfway point, explain that the rule is that you round up.
If the actual number is closer to the higher rounded number, or above the halfway point, we round up. , Circle this number on the number line, and draw an arrow pointing to it from the actual number.
For example, since 892 is above the halfway point, we round up to
900.
So 892 rounded to the nearest hundred is
900.
Draw an arrow pointing from 892 to
900.
Circle
900. , The number should go to at least the same place value students are rounding to.
This part is for students who can think more abstractly about rounding.
It is helpful to use only after students have mastered rounding using a number line.
For example, if students are rounding to the nearest hundred, you might write down the number
892. , Circle the digit in this place value and determine its value.
Ask students what rounded number is above it.
For example, if rounding 892 to the nearest hundred, students should circle the 8, and understand that its value is
800.
Ask, “What hundred is above 800? 900 is above
800.” Emphasize that students are rounding to the nearest hundred. , The place value below gives us the information we need in order to determine whether we round up or down.
It is the deciding digit.
Underline the deciding digit in this place value.
For example, if rounding 892 to the nearest hundred, students should look to the tens place and underline the
9. , If the deciding digit is 5 or more, we round up.
If the deciding digit is 4 or less, we round down.It might be helpful to draw a 5 next to an arrow pointing up, and a 4 next to an arrow pointing down. , Determine whether it is tells you to round up or down.
For example, in the number 892, you would look at the
9.
Since 9 is above 5, it tells you to round up. , Draw an arrow pointing from the original number to the rounded number.
Make sure students can identify what place value they were rounding to.
Students can be confused when rounding down using this method.
For example, they might think they should round 412 down to 300, because 300 is the hundred below
400.
Emphasize that they should consider the original number they are rounding and find the hundred below the original number, not the hundred below the hundreds place of the original number.
For example, 892 rounded to the nearest hundred is
900.
Draw an arrow from 892 to
900. -
Step 3: Count by hundreds to 1
-
Step 4: Continue to practice skip counting other groups of numbers.
-
Step 5: Write a four-digit number.
-
Step 6: Review the ones place.
-
Step 7: Review the tens place.
-
Step 8: Review the hundreds place.
-
Step 9: Review the thousands place.
-
Step 10: Define what rounding is
-
Step 11: and why we use it.
-
Step 12: Explain that we round to a particular place value.
-
Step 13: Choose a number to round.
-
Step 14: Ask students to locate the target place value in the number.
-
Step 15: Draw a number line.
-
Step 16: Ask students to determine the halfway point on the number line.
-
Step 17: Plot the number students are rounding on the number line.
-
Step 18: Ask students if the number is above or below the halfway point on the number line.
-
Step 19: Explain that we round up or down.
-
Step 20: Determine your rounded number.
-
Step 21: Write down the number you are rounding.
-
Step 22: Ask students to locate the target place value in the number.
-
Step 23: Explain that to round
-
Step 24: you look at the place value below (to the right of) the one you are rounding to.
-
Step 25: Explain the rules of rounding.
-
Step 26: Look at the underlined digit in the number.
-
Step 27: Determine the rounded number and write it down.
Detailed Guide
If students needs help, they can use their fingers or manipulatives.
Before learning to round, students must be able to skip count.
Skip counting allows students to identify the nearest ten or nearest hundred to a number that is being rounded.
Students also need to understand the difference between counting by ones, tens, and hundreds, to activate their understanding of place value.
Choose random tens, and ask the students which ten is above it.
Students can use a hundreds chart if need be.
For example, after the students can count by tens to 100, ask, “What ten is above 20? 30 is the ten above
20.” , Choose random hundreds, and ask the students which hundred is above it.
Students can use a thousands chart if need be.
For example, after the students can count by hundreds to 1,000, ask, “What hundred is above 400? 500 is above
400.” , The skip counting you do will depend on the type of rounding you expect the students to do.
For example, if rounding to the ten thousands place, practice skip counting by thousands and ten thousands. , Choose a number that has different digits in each place value, for clarity’s sake.
It is essential that students have a complete understanding of place value before attempting to teach them rounding.
If students have already mastered place value, you can skip this part.
This assumes you are teaching rounding to the tens or hundreds.
If you are teaching rounding to the thousands or more, you might want to write a number that has 5 or more digits.
For example, you might write the number 3,892. , Point to the digit farthest to the right.
Explain the value of the digit in the ones place.
Count by ones until you reach the value.
You can use base 10 blocks or other manipulatives to help illustrate the value of each digit.
For example, in the number 3,892, point to the 2 and explain that the 2 is in the ones place, and the value of 2 twos is
2.
Count: “1,
2.” , Point to the digit second from the right.
Explain the value of the digit in the tens place.
Count by tens until you reach the value.
For example, in the number 3,892, point to the 9 and explain that the 9 is in the tens place, and the value of 9 tens is
90.
Count: “10, 20, 30, 40, 50, 60, 70, 80,
90.” , Point to the digit third from the right.
Explain the value of the digit in the hundreds place.
Count by hundreds until you reach the value.
For example, in the number 3,892, point to the 8 and explain that the 8 is in the hundreds place, and the value of 8 hundreds is
800.
Count: “100, 200, 300, 400, 500, 600, 700,
800.” , Point to the digit fourth from the right.
Explain the value of the digit in the thousands place.
Count by thousands until you reach the value.
For example, in the number 3,892, point to the 3 and explain that the 3 is in the thousands place, and the value of 3 thousands is 3,000.
Count: “1,000, 2,000, 3,000.” , Rounding is changing a difficult number to a number close by.
We round a number to make it easier to use.For example, if you are trying to figure out about how many total cookies you and your friend ate last year, and you ate 327 cookies while your friend ate 286, you could round both numbers to 300, because 300 + 300 is easier to calculate than 327 +
286. , We often round to the nearest ten, hundred, or thousand.
Review what place value the students are rounding to.
For example, you might want student to round to the nearest hundred.
Review where the hundreds place is, if necessary. , The number should go to at least the same place value students are rounding to.
For example, if students are rounding to the nearest hundred, you might choose the number
892. , Determine the value, and ask for the rounded number above it.
For example, if rounding 892 to the nearest hundred, students should locate the 8, and understand that its value is
800.
Ask, “What hundred is above 800? 900 is above
800.” Emphasize that students are rounding to the nearest hundred. , The number on the far left of the line should be the value of the digit in the target place value.
The value on the far right should be the rounded number above it.
Use hash marks to skip count up the number line.
For better accuracy, it is helpful to use preprinted number lines instead of hand-drawn number lines.
For example, if rounding 892 to the nearest hundred, the number on the far left of the number line would be 800, and the number on the far right of the number line would be
900.
In between, the hash marks would skip count by tens: 810, 820, 830, 840, 850, 860, 870, 880, 890,
900. , Mark this point on the line.
You can mark the point with a star or dot, or you can trace over the first half of the number line in one color, and trace the second half of the number line in another color.
For example, if using a number line that begins with 800 and ends with 900, the halfway point would be 850, so you would draw a star on the 850 hash mark. , Use the additional hash marks on the number line to denote other place values as necessary.
Draw a dot on the appropriate hash mark, and write the number above the dot.
For example, if plotting 892, you would draw nine hash marks between 890 and 900, and draw a dot on the second hash mark after
890. , Determine whether the number is closer to the first number on the number line, or the last number on the number line.
For example, ask students if 892 is above or below
850.
Since it is above 850, it is closer to 900 than it is to
800. , Whether we round up or down depends on which rounded number our actual number is closest to.
If the actual number is closer to the lower rounded number, or below the halfway point, we round down.
If the number is exactly at the halfway point, explain that the rule is that you round up.
If the actual number is closer to the higher rounded number, or above the halfway point, we round up. , Circle this number on the number line, and draw an arrow pointing to it from the actual number.
For example, since 892 is above the halfway point, we round up to
900.
So 892 rounded to the nearest hundred is
900.
Draw an arrow pointing from 892 to
900.
Circle
900. , The number should go to at least the same place value students are rounding to.
This part is for students who can think more abstractly about rounding.
It is helpful to use only after students have mastered rounding using a number line.
For example, if students are rounding to the nearest hundred, you might write down the number
892. , Circle the digit in this place value and determine its value.
Ask students what rounded number is above it.
For example, if rounding 892 to the nearest hundred, students should circle the 8, and understand that its value is
800.
Ask, “What hundred is above 800? 900 is above
800.” Emphasize that students are rounding to the nearest hundred. , The place value below gives us the information we need in order to determine whether we round up or down.
It is the deciding digit.
Underline the deciding digit in this place value.
For example, if rounding 892 to the nearest hundred, students should look to the tens place and underline the
9. , If the deciding digit is 5 or more, we round up.
If the deciding digit is 4 or less, we round down.It might be helpful to draw a 5 next to an arrow pointing up, and a 4 next to an arrow pointing down. , Determine whether it is tells you to round up or down.
For example, in the number 892, you would look at the
9.
Since 9 is above 5, it tells you to round up. , Draw an arrow pointing from the original number to the rounded number.
Make sure students can identify what place value they were rounding to.
Students can be confused when rounding down using this method.
For example, they might think they should round 412 down to 300, because 300 is the hundred below
400.
Emphasize that they should consider the original number they are rounding and find the hundred below the original number, not the hundred below the hundreds place of the original number.
For example, 892 rounded to the nearest hundred is
900.
Draw an arrow from 892 to
900.
About the Author
Brian Wright
Brian Wright specializes in education and learning and has been creating helpful content for over 5 years. Brian is committed to helping readers learn new skills and improve their lives.
Rate This Guide
How helpful was this guide? Click to rate: