Round

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How to Round Whole Numbers
A Number Line
When rounding number, some times it helps to
remember and to use a number line.
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0
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100 200
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1 000 000
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10 20 30 40 50 60 70 80 90 100
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300
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400
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500
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2 000 000
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600
|
700
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800
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900 1000
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3 000 000
BASIC RULES
1. If the number to the RIGHT of the Rounding Number is 5 or
more (5, 6, 7 8 or 9) then the LEFT (Rounding Number) number
goes UP by ONE place.
2. If the number to the RIGHT of the Rounding Number is 4 or less
(4, 3, 2, 1 or 0) then the LEFT (Rounding Number) number
remains the SAME.
3. Every number AFTER the Rounding Number becomes 0.
4. Everything BEFORE the Rounding Number remains the same.
5. If the Rounding Number is a 9 and it goes up by one, then a 0 is
placed in the Rounding Number Place and 1 is moved to the next
place to the LEFT. (same as carrying in adding)
How to Round Whole Numbers to the Tens Place
Example: Round 78 to the nearest tens place
| | | | | | | | | |
78 80
70
Use a number line to help you visualize
1. Underline the place you want to round to.
Here we want the tens place
78
How to Round Whole Numbers to the Tens Place
Example: Round 78 to the nearest tens place
2. Look to the right of the place you want to round to,
Look
here
Now look to the right of the
78
tens place
- If the digit is 5, 6, 7, 8 or 9 – the digit in the tens place
goes UP by 1
- If the digit is 0, 1, 2, 3 or 4 – the digit in the tens place
STAYS THE SAME
The 7 in the tens place
goes up by 1 to 8
78
80
How to Round Whole Numbers to the Tens Place
Example: Round 78 to the nearest tens place
3. Next, the digits to the right of the rounding place become
zero.
Now the 8 becomes zero
78 becomes
80
4. Anything to the left of the rounding place remains the
same.
So 78 rounded to the nearest tens place is 80
How to Round Whole Numbers to the Tens Place
Example: Round 123 to the nearest tens place
| | | | | | | | | |
130
120
123
To Round:
Look to the right
On the left
123
Here is the tens place
3, so the 2 in the tens
place stays the same.
On the left hand side, all
stays the same
 123 rounds to 120
How to Round Whole Numbers to the Tens Place
Example: Round 1 099 to the nearest tens place
| | | | | | | | | |
1090
1099 1100
To Round:
1099 Here is the tens place with 9 to its right
The 9 in the tens place goes up by one.
**But, 9 goes to 10 and we only have one place
1100 So we need to move over one more place to the
left adding 1 to the hundreds place and 0 to the
tens place. All on right changes to zero.
 1 099 rounds to 1 100
How to Round Whole Numbers to the Tens Place
Example: Round the following to the nearest tens place
To Round:
2
65
234
2 343
45 678
65 723
199 789
1 222 222
__2
65
234
2 343
45 678
65 723
199 789
1 222 222
0
70
230
2 340
45 680
65 720
199 790
1 222 220
Look to the value of the place to the right of the tens place
Round the following numbers to the nearest tens place.
a) 45
b) 67
a) 50
b) 70
c) 123
c) 120
d) 456
d) 460
e) 890
e) 890
f) 1232
f) 1 230
How to Round Whole Numbers to the Hundreds Place
Example: Round 145 to the nearest hundreds place
| | | | | | | | | |
200
100
145
Use a number line to help you visualize
1. Underline the place you want to round to.
Here we want the hundreds place
145
How to Round Whole Numbers to the Hundreds Place
Example: Round 145 to the nearest hundreds place
2. Look to the right of the place you want to round to,
Now look to the right of the
tens place
145
- If the digit is 5, 6, 7, 8 or 9 – the digit in the hundreds
place goes UP by 1
- If the digit is 0, 1, 2, 3 or 4 – the digit in the hundreds
place STAYS THE SAME
The 1 in the hundreds place
stays the same
145
100
How to Round Whole Numbers to the Hundreds Place
Example: Round 145 to the nearest hundreds place
3. Next, the digits to the right of the rounding place become
zero.
Now the 4 and 5 becomes zero
145 becomes
100
4. Anything to the left of the rounding place remains the
same.
So 145 rounded to the nearest hundreds place is 100
How to Round Whole Numbers to the Hundreds Place
Example: Round the following to the nearest hundreds
place
To Round:
2
65
234
2 343
45 678
65 723
199 789
1 222 222
__2
_65
234
2 343
45 678
65 723
199 789
1 222 222
0
100
200
2 300
45 700
65 700
199 800
1 222 200
Look to the value of the place to the right of the hundreds place
Round the following numbers to the nearest hundreds place.
a) 49
a) 0
b) 136
b) 100
c) 293
c) 300
d) 456
d) 500
e) 1 890
e) 1 900
f) 12 345
f) 12 300
How to Round Whole Numbers to the
Thousands Place
Example: Round 9 871 to the nearest thousands place
| | | | | | | | | | |
9000
9 871 10 000
Use a number line to help you visualize
1. Underline the place you want to round to.
Here we want the thousands
9 871
How to Round Whole Numbers to the
Thousands Place
Example: Round 9 871 to the nearest thousands place
2. Look to the right of the place you want to round to,
Now look to the right of the
thousands place
9 871
- If the digit is 5, 6, 7, 8 or 9 – the digit in the thousands
place goes UP by 1
- If the digit is 0, 1, 2, 3 or 4 – the digit in the thousands
place STAYS THE SAME
The 9 in the thousands place
goes up by 1
9 871
10 000
How to Round Whole Numbers to the
Thousands Place
Example: Round 9 871 to the nearest thousands place
3. Next, the digits to the right of the rounding place become
zero.
Now the 8,7 and 1 becomes zero 9 871 becomes 10 000
4. Anything to the left of the rounding place remains the
same.
So 9 871 rounded to the nearest thousand place is 10 000
How to Round Whole Numbers to the Thousands Place
Example: Round the following to the nearest thousands
place
To Round:
2
65
234
2 343
45 678
65 723
199 789
1 222 222
___2
_ _65
_234
2 343
45 678
65 723
199 789
1 222 222
0
0
0
2 000
46 000
66 000
200 000
1 222 000
Look to the value of the place to the right of the thousands place
Round the following numbers to the nearest thousands place.
a) 1 234
a) 1 000
b) 78 902
b) 79 000
c) 12 666
c) 13 000
d) 9 987
d) 10 000
e) 2 890
e) 3 000
f) 1 234 512
f) 1 235 000
How to Round Whole Numbers to the
Ten Thousands Place
Example: Round 19 012 to the nearest ten thousands place
| | | | | | | | | |
20 000
19 000
19 012
Use a number line to help you visualize
1. Underline the place you want to round to.
Here we want the ten thousands place
19 012
How to Round Whole Numbers to the
Ten Thousands Place
Example: Round 19 012 to the nearest ten thousands place
2. Look to the right of the place you want to round to,
Now look to the right of the
ten thousands place
19 012
- If the digit is 5, 6, 7, 8 or 9 – the digit in the ten
thousands place goes UP by 1
- If the digit is 0, 1, 2, 3 or 4 – the digit in the ten
thousands place STAYS THE SAME
The 1 in the ten thousands place
goes up by one
19 012
20 000
How to Round Whole Numbers to the
Ten Thousands Place
Example: Round 19 012 to the nearest ten thousands place
3. Next, the digits to the right of the rounding place become
zero.
All the numbers on the
right becomes zero
19 012 becomes
20 000
4. Anything to the left of the rounding place remains the
same.
So 19 012 rounded to the nearest ten thousands
place is 20 000
How to Round Whole Numbers to the Ten Thousands Place
Example: Round the following to the nearest ten
thousands place
To Round:
2
65
234
2 343
45 678
65 723
199 789
1 222 222
__2
_65
234
2 343
45 678
65 723
199 789
1 222 222
0
70
230
2 340
45 680
65 720
199 790
1 222 220
Look to the value of the place to the right of the tens place
Round the following numbers to the nearest ten thousands
place.
a) 45 653
a) 50 000
b) 567 809
b) 570 000
c) 12 342 565
c) 12 340 000
d) 456 789
d) 460 000
e) 112 343
e) 110 000
How to Round Whole Numbers to the
Hundred Thousands Place
Example: Round 145 to the nearest hundreds place
| | | | | | | | | |
200
100
145
Use a number line to help you visualize
1. Underline the place you want to round to.
Here we want the hundreds place
145
How to Round Whole Numbers to the
Hundred Thousands Place
Example: Round 145 to the nearest hundreds place
2. Look to the right of the place you want to round to,
Now look to the right of the
tens place
145
- If the digit is 5, 6, 7, 8 or 9 – the digit in the hundreds
place goes UP by 1
- If the digit is 0, 1, 2, 3 or 4 – the digit in the hundreds
place STAYS THE SAME
The 1 in the hundreds place
stays the same
145
100
How to Round Whole Numbers to the
Hundred Thousands Place
Example: Round 145 to the nearest hundreds place
3. Next, the digits to the right of the rounding place become
zero.
Now the 4 and 5 becomes zero
145 becomes
100
4. Anything to the left of the rounding place remains the
same.
So 145 rounded to the nearest hundreds place is 100
How to Round Whole Numbers to the Hundred Thousands
Place
Example: Round the following to the nearest hundred
thousands place
To Round:
2
65
234
2 343
45 678
65 723
199 789
1 222 222
__2
_65
234
2 343
45 678
65 723
199 789
1 222 222
0
70
230
2 340
45 680
65 720
199 790
1 222 220
Look to the value of the place to the right of the tens place
Round the following numbers to the nearest hundred
thousands place.
a) 455 555
a) 500 000
b) 156 789
b) 200 000
c) 12 345 876
c) 12 300 000
d) 12 000 542
e) 334 334
d) 12 000 000
e) 300 000
How to Round Whole Numbers to the Millions Place
Example: Round 145 to the nearest hundreds place
| | | | | | | | | |
200
100
145
Use a number line to help you visualize
1. Underline the place you want to round to.
Here we want the hundreds place
145
How to Round Whole Numbers to the Millions Place
Example: Round 145 to the nearest hundreds place
2. Look to the right of the place you want to round to,
Now look to the right of the
tens place
145
- If the digit is 5, 6, 7, 8 or 9 – the digit in the hundreds
place goes UP by 1
- If the digit is 0, 1, 2, 3 or 4 – the digit in the hundreds
place STAYS THE SAME
The 1 in the hundreds place
stays the same
145
100
How to Round Whole Numbers to the Millions Place
Example: Round 145 to the nearest hundreds place
3. Next, the digits to the right of the rounding place become
zero.
Now the 4 and 5 becomes zero
145 becomes
100
4. Anything to the left of the rounding place remains the
same.
So 145 rounded to the nearest hundreds place is 100
How to Round Whole Numbers to the Millions Place
Example: Round the following to the nearest millions
place
To Round:
2
65
234
2 343
45 678
65 723
199 789
1 222 222
__2
_65
234
2 343
45 678
65 723
199 789
1 222 222
0
70
230
2 340
45 680
65 720
199 790
1 222 220
Look to the value of the place to the right of the tens place
Round the following numbers to the nearest millions place.
a) 1 455 555
a) 1 000 000
b) 34 156 789
b) 34 000 000
c) 999 999
c) 1 000 000
d) 13 567 789
d) 14 000 000
e) 27 800 000
e) 28 000 000
How to Round Whole Numbers
Example: Round 78 to the nearest tens place
| | | | | | | | | | | |
78 80
70
Use a number line to help you visualize
1. Underline the place you want to round to.
Here we want the tens place
78
Some Examples:
1. Round to the nearest 10
12 ____________
Or use a number line is 12 closer to 10 or to 20?
Examples
Because ...
3.1416 rounded to hundredths is 3.14
... the next digit (1) is less than 5
1.2635 rounded to tenths is 1.3
... the next digit (6) is 5 or more
1.2635 rounded to 3 decimal places is 1.264
... the next digit (5) is 5 or more
134.9 rounded to tens is 130
... the next digit (4) is less than 5
12,690 rounded to thousands is 13,000
... the next digit (6) is 5 or more
1.239 rounded to units is 1
... the next digit (2) is less than 5
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