What is the value of each place in the number 634?

Hundreds place: 600, tens place: 30, ones place: 4.

Draw a number line to show 634.

Students could draw a number line showing a tick mark for each number between 630 and 640 and label the tick mark for 634.

Which of these numbers is greater, 207 or 250? Explain.

The hundreds place is the same in both numbers, so I need to compare the tens place. There are 0 tens in 207 and there are 5 tens in 250. 5 tens is greater than 0 tens, so 250 is greater than 207.

Which number is greater, 948 or 899? Explain.

The digits in the hundreds place in each number are different, so I can compare the digits in the hundreds place. 9 is in the hundreds place in 948. 8 is in the hundreds place in 899. 9 is greater than 8, so 948 is greater than 899.

Jaffar says that 99 is greater than 200 because 99 has 2 nines and 200 has 2 zeros, and 9 is greater than 0. Is Jaffar correct? Explain.

Jaffar is not correct. The way to compare numbers is to start with the greatest place first and compare the digits in that place. If the digits are the same, move on to the next digit to the right. In this case, the digit 2 is in the hundreds place in 200. There is no digit in the hundreds place in 99. This is the same as having 0 in the hundreds place. So we can compare the digits in the hundreds place. 2 is greater than 0, so 200 is greater than 99.

How can you draw and label a number line to help you round 378 to the nearest ten?

Draw a number line from 370 to 380. Put a tick mark in the middle and label it 375. 378 is greater than 375, so plot the point for 378 between 375 and 380. 378 is closer to 380 than 370, so 378 rounds up to 380.

What are the rules for rounding?

Look to the right of the place you want to round to. If the digit in that place is 5 or greater, round up. If the digit in that place is less than 5, round down.

What steps would you go through to round 645 to the nearest ten using the rules?

First I look at the tens place, which has the digit 4. The place to the right of that place is the ones place, and it has a 5. When I have a 5 in the place to the right, I round up, so 645 rounded to the nearest ten is 650.

Rounding (Nearest 10 and 100)

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What you will learn from this videoWhat you will learn

How to round to the nearest 10 and the nearest hundred.
Rounding can make numbers more understandable to work with.
We'll discover that this knowledge can let us count how many balloons are at a party, how many animals live on a farm & even how many toys are in a toy store!

Discussion Questions
- Before Video
  What is the value of each place in the number 634?ANSWER
  - Hundreds place: 600, tens place: 30, ones place: 4.
  Draw a number line to show 634.ANSWER
  - Students could draw a number line showing a tick mark for each number between 630 and 640 and label the tick mark for 634.
  Which of these numbers is greater, 207 or 250? Explain.ANSWER
  - The hundreds place is the same in both numbers, so I need to compare the tens place. There are 0 tens in 207 and there are 5 tens in 250. 5 tens is greater than 0 tens, so 250 is greater than 207.
  Which number is greater, 948 or 899? Explain.ANSWER
  - The digits in the hundreds place in each number are different, so I can compare the digits in the hundreds place. 9 is in the hundreds place in 948. 8 is in the hundreds place in 899. 9 is greater than 8, so 948 is greater than 899.
  Jaffar says that 99 is greater than 200 because 99 has 2 nines and 200 has 2 zeros, and 9 is greater than 0. Is Jaffar correct? Explain.ANSWER
  - Jaffar is not correct. The way to compare numbers is to start with the greatest place first and compare the digits in that place. If the digits are the same, move on to the next digit to the right. In this case, the digit 2 is in the hundreds place in 200. There is no digit in the hundreds place in 99. This is the same as having 0 in the hundreds place. So we can compare the digits in the hundreds place. 2 is greater than 0, so 200 is greater than 99.
- After Video
  How can you draw and label a number line to help you round 378 to the nearest ten?ANSWER
  - Draw a number line from 370 to 380. Put a tick mark in the middle and label it 375. 378 is greater than 375, so plot the point for 378 between 375 and 380. 378 is closer to 380 than 370, so 378 rounds up to 380.
  What are the rules for rounding?ANSWER
  - Look to the right of the place you want to round to. If the digit in that place is 5 or greater, round up. If the digit in that place is less than 5, round down.
  What steps would you go through to round 645 to the nearest ten using the rules?ANSWER
  - First I look at the tens place, which has the digit 4. The place to the right of that place is the ones place, and it has a 5. When I have a 5 in the place to the right, I round up, so 645 rounded to the nearest ten is 650.
  Write the greatest number that rounds to 800 when rounding to the nearest hundred.ANSWER
  - 849.
  Tarek wrote a 3-digit number on a piece of paper. The digits are 5, 2, and 7. The number rounded to the nearest ten is 260. What is the number that Tarek wrote? ANSWER
  - 257.
Vocabulary
- Rounding DEFINE
- Nearest ten DEFINE
- Nearest hundred DEFINE
- Number line DEFINE
- Halfway point DEFINE
- Ones place DEFINE
- Tens place DEFINE
- Hundreds place DEFINE
- Round up DEFINE
- Round down DEFINE
Reading Material
Practice Word Problems
Practice Number Problems
Lesson Plan
Teacher Guide
Assessment
Online Quiz Game Quiz PDF Exit Ticket