How to Round Whole Numbers
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Transcript of How to Round Whole Numbers
How to Round Whole Numbers
A Number LineWhen rounding number, some times it helps to
remember and to use a number line.
| | | | | | | | | | | 0 10 20 30 40 50 60 70 80 90 100
| | | | | | | | | | 100 200 300 400 500 600 700 800 900 1000
| | | 1 000 000 2 000 000 3 000 000
BASIC RULES1. 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
Use a number line to help you visualize
Example: Round 78 to the nearest tens place
| | | | | | | | | | 70 8078
1. Underline the place you want to round to.
Here we want the tens place 78
Example: Round 78 to the nearest tens place
2. Look to the right of the place you want to round to,
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
Look here
The 7 in the tens place 78 80 goes up by 1 to 8
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
| | | | | | | | | | 120 130123
To Round: 123 Here is the tens placeLook to the right 3, so the 2 in the tens place stays the same.On the left On the left hand side, all stays the same
123 rounds to 120
How to Round Whole Numbers to the Tens Place
How to Round Whole Numbers to the Tens Place
Example: Round 1 099 to the nearest tens place
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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
1090 11001099
How to Round Whole Numbers to the Tens Place
Example: Round the following to the nearest tens place
To Round: 265234 2 34345 67865 723199 7891 222 222
070230 2 34045 68065 720199 7901 222 220
__265234 2 34345 67865 723199 7891 222 222
Look to the value of the place to the right of the tens place
PRACTICERound the following numbers to the nearest tens place.
a) 45
b) 67
c) 123
d) 456
e) 890
f) 1232
b) 70
a) 50
c) 120
d) 460
e) 890
f) 1 230
How to Round Whole Numbers to the Hundreds Place
Use a number line to help you visualize
Example: Round 145 to the nearest hundreds place
| | | | | | | | | | 100 200145
1. Underline the place you want to round to.
Here we want the hundreds place 145
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 145 tens place - 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 145 100 stays the same
How to Round Whole Numbers to the 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 145 to the nearest hundreds place
How to Round Whole Numbers to the Hundreds Place
Example: Round the following to the nearest hundreds place
To Round: 265234 2 34345 67865 723199 7891 222 222
0100200 2 30045 70065 700199 8001 222 200
_ _ 2_65234 2 34345 67865 723199 7891 222 222
Look to the value of the place to the right of the hundreds place
PRACTICERound the following numbers to the nearest hundreds place.
a) 49
b) 136
c) 293
d) 456
e) 1 890
f) 12 345
b) 100
a) 0
c) 300
d) 500
e) 1 900
f) 12 300
How to Round Whole Numbers to the Thousands Place
Use a number line to help you visualize
Example: Round 9 871 to the nearest thousands place
| | | | | | | | | | | 9000 10 0009 871
1. Underline the place you want to round to.
Here we want the thousands 9 871
2. Look to the right of the place you want to round to,
Now look to the right of the 9 871 thousands place - 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 9 871 10 000 goes up by 1
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 9 871 to the nearest thousands place
How to Round Whole Numbers to the Thousands Place
Example: Round the following to the nearest thousands place
To Round: 265234 2 34345 67865 723199 7891 222 222
000 2 00046 00066 000200 0001 222 000
_ _ _ 2_ _65_234 2 34345 67865 723199 7891 222 222
Look to the value of the place to the right of the thousands place
PRACTICERound the following numbers to the nearest thousands place.
a) 1 234
b) 78 902
c) 12 666
d) 9 987
e) 2 890
f) 1 234 512
b) 79 000
a) 1 000
c) 13 000
d) 10 000
e) 3 000
f) 1 235 000
Use a number line to help you visualize
Example: Round 19 012 to the nearest ten thousands place
| | | | | | | | | | 19 000 20 000
19 012
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
2. Look to the right of the place you want to round to,
Now look to the right of the 19 012 ten thousands place - 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 19 012 20 000goes up by one
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 19 012 becomes 20 000right becomes zero4. 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 19 012 to the nearest ten thousands place
How to Round Whole Numbers to the Ten Thousands Place
Example: Round the following to the nearest ten thousands place
To Round: 265234 2 34345 67865 723199 7891 222 222
070230 2 34045 68065 720199 7901 222 220
_ _ 2_65234 2 34345 67865 723199 7891 222 222
Look to the value of the place to the right of the tens place
PRACTICERound the following numbers to the nearest ten thousands
place.
a) 45 653
b) 567 809
c) 12 342 565
d) 456 789
e) 112 343
b) 570 000
a) 50 000
c) 12 340 000
d) 460 000
e) 110 000
Use a number line to help you visualize
Example: Round 145 to the nearest hundreds place
| | | | | | | | | | 100 200145
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 145 tens place - 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 145 100 stays the same
How to Round Whole Numbers to the Hundred Thousands 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
Example: Round 145 to the nearest hundreds place
How to Round Whole Numbers to the Hundred Thousands Place
How to Round Whole Numbers to the Hundred Thousands Place
Example: Round the following to the nearest hundred thousands place
To Round: 265234 2 34345 67865 723199 7891 222 222
070230 2 34045 68065 720199 7901 222 220
_ _ 2_65234 2 34345 67865 723199 7891 222 222
Look to the value of the place to the right of the tens place
PRACTICERound the following numbers to the nearest hundred
thousands place.
a) 455 555
b) 156 789
c) 12 345 876
d) 12 000 542
e) 334 334
b) 200 000
a) 500 000
c) 12 300 000
d) 12 000 000
e) 300 000
Use a number line to help you visualize
Example: Round 145 to the nearest hundreds place
| | | | | | | | | | 100 200145
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 145 tens place - 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 145 100 stays the same
How to Round Whole Numbers to the Millions 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
Example: Round 145 to the nearest hundreds place
How to Round Whole Numbers to the Millions Place
How to Round Whole Numbers to the Millions Place
Example: Round the following to the nearest millions place
To Round: 265234 2 34345 67865 723199 7891 222 222
070230 2 34045 68065 720199 7901 222 220
_ _ 2_65234 2 34345 67865 723199 7891 222 222
Look to the value of the place to the right of the tens place
PRACTICERound the following numbers to the nearest millions place.
a) 1 455 555
b) 34 156 789
c) 999 999
d) 13 567 789
e) 27 800 000
b) 34 000 000
a) 1 000 000
c) 1 000 000
d) 14 000 000
e) 28 000 000
How to Round Whole Numbers
Use a number line to help you visualize
Example: Round 78 to the nearest tens place
| | | | | | | | | | | |70 8078
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