In third grade, students learn to round to tens and hundreds.Rounding is an important skill that students struggle with because they don't have the skills to do it.Ensuring students have prior knowledge is important when teaching rounding.You can teach rounding with a number line.Students should be taught the rules, methods, and tricks of rounding after mastering these skills.
Step 1: Count by the number of them.
If students need help, they can use their hands.Students must be able to skip count before learning to round.Students can skip count to find the nearest ten or hundred to a number.The difference between counting by ones, tens, and hundreds is important for students to understand place value.
Step 2: Count by the number of people.
Ask the students which ten is above it.A hundreds chart can be used by students.After the students can count by tens to 100, ask, "What ten is above 20?"There are ten above 20.
Step 3: It should be counted by hundreds to 1,000.
Ask the students which hundred is above it.The students can use a chart.After the students can count by hundreds to 1,000, ask, "What hundred is above 400?"500 is above 400.
Step 4: Don't count other groups of numbers.
The type of rounding you expect the students to do will affect the skip counting you do.If rounding to the ten thousands place, skip counting by thousands and ten thousand.
Step 5: Write a number on a piece of paper.
For clarity's sake, choose a number with different digits.Students need to have a complete understanding of place value before they can teach rounding.You can skip this part if students have mastered place value.If you are teaching rounding to the tens or hundreds, this is correct.If you are teaching rounding to thousands or more, you might want to write a number that has more than one digit.You can write the number 3,892.
Step 6: The ones place should be reviewed.
To the right, point to the digit.Give the value of the digit.Until you reach the value, count by them.Base 10 blocks can be used to show the value of each digit.In the number 3,892, point to the 2 and explain that the value of 2 twos is 2.Count: 1, 2.
Step 7: Take a look at the tens place.
The digit second is from the right.Explain the value of the digit.You have to count by tens until you reach the value.In the number 3,892, point to the 9 and explain that it's in the tens, and the value of 9 tens is 90.The count was 10, 20, 30, 40, 50, 60, 70, 80, 90.
Step 8: Take a look at the hundreds place.
The digit third is from the right.The digit is in the hundreds.Until you reach the value, count by hundreds.In the number 3,892, point to the 8 and explain that it is in the hundreds, and the value of 8 is 800.There are 100, 200, 300, 400, 500, 600, 700, 800.
Step 9: Take a quick look at the thousands place.
From the right, point to the digit fourth.Explain the value of the digit.When you reach the value, count by thousands.In the number 3,892, point to the 3 and explain that it's in the thousands and the value is 3000.The count was 1,000, 2,000, and 3,000.
Step 10: What is rounding, and why do we use it?
Changing a difficult number to a number close by is rounding.To make it easier to use, we round a number.If you want to figure out how many cookies you and your friend ate last year, you can round both numbers to 300.
Step 11: Explain what the place value is.
We usually round to the nearest hundred or thousand.The students are rounding to a value.You might want the student to round to the nearest hundred.If necessary, review where the hundreds are.
Step 12: To round, choose a number.
The number should go to the place value students are rounding to.If students are rounding to the nearest hundred, you could choose the number 892.
Step 13: The students should find the target place value in the number.
Ask for a rounded number above the value.Students should know that the 8 is worth 800 if they round 892 to the nearest hundred.What number is above 800?The students are rounding to the nearest hundred.
Step 14: A number line can be drawn.
The digit in the target place value should be the number on the far left of the line.The rounded number should be the value on the far right.If you want to skip counting up the number line, use hash marks.It is helpful to use preprinted number lines for better accuracy.The number on the far right of the number line would be 900 if 892 was rounded to the nearest hundred.The count would be skipped by tens if the marks were not present.
Step 15: Students are asked to figure out the halfway point on the number line.
The point is on the line.You can either mark the point with a star or dot, or you can trace the second half of the number line in a different color.If you use 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.
Step 16: Students are rounding the number line.
The number line has additional marks on it to indicate other place values.Write the number above the dot on the appropriate hash mark.If you plotted 892, you would draw nine marks between 890 and 900, and then draw a dot on the second mark.
Step 17: Ask students if the number is above or below the halfway point.
Determine if the number is close to the first number or the last number.Ask students if 892 is above or below 850.It is close to 900 since it is above 800.
Step 18: Tell us how we round up or down.
Depending on which rounded number our actual number is closest to, we can either round up or down.We round down if the number is closer to the lower rounded number or below the halfway point.The rule is that you round up if the number is at the halfway point.We round up if the number is close to the higher rounded number or above the halfway point.
Step 19: Determine the number.
An arrow points to the actual number when you circle it on the number line.Since 892 is above the halfway point, we go up to 900.900 is rounded to the nearest hundred.An arrow points from 892 to 900.The circle is 900.
Step 20: Write down the number that is being rounded.
The number should be the same as the place value students are rounding to.Students who can think abstractly about rounding will find this part useful.After students have mastered rounding using a number line, it is helpful to use.If students are rounding to the nearest hundred, you can write down the number 892.
Step 21: The students should find the target place value in the number.
Determine the value of the digit by circleing it in the place value.Ask students what the rounded number is.Students should circle the 8 if they want to understand the value of 800.Ask what number is above 800.Students are rounding to the nearest hundred.
Step 22: To round, look at the place value below the one you are rounding to.
The information we need to determine whether we round up or down is given by the place value.The digit is the most important.The deciding digit is in this place value.Students should look at the tens place if rounding to the nearest hundred.
Step 23: The rules of rounding are explained.
We round up if the digit is 5 or more.We round down if the digit is less than 4.It would be helpful to draw a 5 next to an arrow pointing up and a 4 down.
Step 24: The digit is highlighted in the number.
Determine if it tells you to round up or down.You would look at the 9 in the number 892.It tells you to round up if 9 is above 5.
Step 25: Write the rounded number down.
An arrow points from the original number to the rounded one.Students should be able to identify what place value they were rounding to.When rounding down, students can be confused.They might think they should go down to 300 because it's the hundred below 400.They should consider the original number when rounding it, not the hundred below it.892 rounded to the nearest hundred is 900.An arrow should be drawn from 892 to 900.