1. Rounding Whole Numbers

2. What is rounding? Rounding means changing a given number to the nearest ten, hundred, thousand, and so on.
When rounding a number, you first need to ask: what are you rounding it to? Numbers can be rounded to the nearest ten, the nearest hundred, the nearest thousand, and so on.

3. To round a number to a given place:
Step 1: Find the place you are rounding to: ten, hundred, thousand or another place value.
ie: Round 6,458 to the nearest hundred - In this case we are rounding to the hundred's place.
Step 2: Decide what two multiples the number you are rounding is between.
ie: We are rounding to the hundred's place so we would choose multiples of 100. So:
6,458 is between 6,400 and 6,500

4. Step 3 Look at the digit to its right.
If the number you are rounding is followed by , 6, 7, 8, or 9, round the number up to the higher multiple.
If the number you are rounding is followed by 0, 1, 2, 3, or 4, round the number down.
ie: Look in the ten place of the number 6,458. We see a 5, so we must round to the higher number.
Therefore: Round 6,458 to the nearest hundred = 6,500
On a number line, you can see how rounding a number approximates its value.

5. You can use a number line to round a whole number to a given place.
2,683
Round 2,683 to the nearest hundred.
First, find the rounding place.
2683
Hundreds

6. Then, find the number on a number line. 2,683 is between 2600 and 2,700

7. Round the number to the closest hundred on the number line.
2,700 is the closest hundred.
Round 2,683 up to 2,700.

8. Hint: If a number is located directly in the middle of the number line, round up.

9. All the numbers to the right of the place you are
Round 13,528 to the nearest ten.
13, > 5
Round up
13,530 to 13,530
Round 13,528 to the nearest hundred
13, < 5
Round down
13,500 to 13,500.
Round 13,528 to the nearest thousand.
13,528 5=5
14,000 to 14,000
All the numbers to the right of the place you are
rounding to become zeros.

10. Here are some more examples:
Consider the number 4,827.
4,827 rounded to the nearest ten is 4,830
4,827 rounded to the nearest hundred is 4,800
4,827 rounded to the nearest thousand is 5,000
Here are some more examples:
34 rounded to the nearest ten is 30
6,809 rounded to the nearest hundred is 6,800
1,951 rounded to the nearest thousand is 2,000

11. Why would you want to round a number?
Rounding is a form of estimation that you use when an approximation is good enough.
For example when you are buying a TV at the store. The cost
might be marked at $ You could say it is about $
Rounding is also good to use so that you know what to expect
for an answer. It is good to use this skill when you are plugging
numbers into a calculator.
Ex. Let's say you are adding up your expenses for the month.
Power: $230, Telephone: $79.68 Rent: $470 Car Payment:
$822. To get a good approximation of the money you will need
you could round to the closest hundred:
Power: $230 would be$200 Phone $79.68 would be $100 Rent: $470 would be $500 Car: $822 would be $800
Total: $1601 which is close to the estimated total of $1600

12. http://www. youtube. com/watch. v=UP7YmXJc7Ik http://www. youtube

13. Activity

14. 1. Round to the nearest thousand: a) ________ d) 9,520 _________ b) ________ e) 56,239 _________ c) ________ f) _________ 2. Round to the nearest ten thousand: a) _________ d) _________ b) _________ e) _________ c) _________ f) _________ 3. Round to the nearest ten: a) 89 _________ d) 514 _________ b) _________ e) 97 _________ c) 265 _________ f) _________

15. 4. Round to the nearest hundred:
a) _________ d) _________
b) _________ e) _________
c) _________ f) _________
5. Round to the nearest hundred thousand:
a) _________ d) _________
b) _________ e) _________
c) _________ f) _________