Transcript Rounding Numbers - Education Extras

By: J’aime Holderbaum
Rounding Numbers to the Nearest
Ten, Hundred, and Thousand
• Project Title: Rounding Numbers
• Audience:
– This presentation is for third grade students.
• Instructional Objectives:
– MAT.IV.1.E2 Investigate and develop an
understanding of the base ten place value
system
• Round whole numbers to the nearest thousand
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What is rounding numbers?
You can estimate when you need to know
about how many or about how much.
Rounding is one way to estimate.
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Rounding to the Nearest Ten
You estimate which ten the number you are rounding is closest to.
If you saw a road sign that said Flint was 17 miles away, then you
could say that Flint is about 20 miles away.
Flint 17 miles
10
11
12
13
14
15
16
17
18
19
17 rounds to 20
Because 17 is closer to 20 than 10
continue
20
Look at these examples. Try to
determine what the rule is for
rounding to the nearest ten.
12 rounds to 10
24 rounds to 20
33 rounds to 30
51 rounds to 50
80 rounds to 80
91 rounds to 90
43 rounds to 40
64 rounds to 60
Choose the rule:
A
B
If the number in the ones column
is 0, 1, 2, 3, or 4 then round
up to the greater ten.
If the number in the ones column
is 0,1,2,3, or 4, then round
down to the lesser ten.
Sorry.
Look at the numbers in the ones column. Do
they cause the number to be rounded to the
lesser ten or the greater ten.
Click here to try again.
Yes!! You are correct. When a number
has a 0, 1, 2, 3, or 4 in the ones
column you round to the lesser ten! For
example 83 rounds to 80.
Click here to continue
Look at these examples. Try to
determine what the rule is for
rounding to the nearest ten.
9 rounds to 10
17 rounds to 20
25 rounds to 30
48 rounds to 50
76 rounds to 80
88 rounds to 90
36 rounds to 40
Choose the rule:
A
If the number in the ones
column is 5, 6, 7, 8, or 9 then
round up to the greater ten.
B
If the number in the ones
column is 5, 6, 7, 8, or 9 then
round down to the lesser ten.
Sorry.
Look at the numbers in the ones column. Do
they cause the number to be rounded to the
lesser ten or the greater ten
Click here to try again
• Yes!! You are correct. When a
number has a 0, 1, 2, 3, or 4 in
the ones column you round to
the lesser ten! For example 83
rounds to 80.
Click here to continue
Think of rounding like a car going over a hill. If you are to round 54 to
the nearest ten, then your choices are either round back to 50 or up to
60. You always need to look at the number in the ones column. If the
car goes up to 54 and stops, then it will roll back to 50.
54 rounds to 50
Click here to continue
54
53
52
55
56
57
58
51
50
59
60
Here is another example. If you are to round 87 to the nearest ten,
then your choices are either round back to 80 or up to 90. If the car
goes to 87 and stops, then it will roll to 90.
87 rounds to 90
Click here to continue
84
83
82
85
86
87
88
81
80
89
90
Now it’s your turn to round to the
nearest ten!
Round 32
A
35
B
30
C
40
Sorry.
Remember the rules:
1. If the number you are rounding is
followed by a 0, 1, 2, 3, or 4, then
round down .
2. If the number you are rounding is
followed by a 5, 6, 7, 8, or9, then
round up.
Click here to try again
Yes!! You are correct.
Click here to continue
Now it’s your turn to round to the
nearest ten!
Round 67
A
70
B
100
C
60
Sorry.
Remember the rules:
1. If the number you are rounding is
followed by a 0, 1, 2, 3, or 4, then
round down .
2. If the number you are rounding is
followed by a 5, 6, 7, 8, or9, then
round up.
Click here to try again
Yes!! You are correct.
Click here to continue
Now it’s your turn to round to the
nearest ten!
Round 25
A
20
B
50
C
30
Sorry.
Remember the rules:
1. If the number you are rounding is
followed by a 0, 1, 2, 3, or 4, then
round down .
2. If the number you are rounding is
followed by a 5, 6, 7, 8, or9, then
round up.
Click here to try again
Yes!! You are correct.
Click here to continue
Next you will learn about
rounding to the nearest hundred.
When rounding to the nearest hundred, you
are finding out which hundred a number is
closest to.
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Rounding to the Nearest
Swartz Creek
Hundred
230 miles
You estimate which hundred the number you are
rounding is closest to. If you saw a road sign that
said Swartz Creek was 230 miles away, then you
could say that Swartz Creek is about 200 miles
away.
200
210
220
230
240
250
260
270
280
290
230 is closer to 200
230 rounds to 200
continue
300
Look at these examples. Try to
determine what the rule is for
rounding to the nearest hundred.
241 rounds to 200
532 rounds to 500
333 rounds to 300
710 rounds to 700
912 rounds to 900
829 rounds to 800
101 rounds to 100
427 rounds to 400
Choose the rule:
A
B
If the number in the tens column
is 0, 1, 2, 3, or 4 then round
up to the greater hundred.
If the number in the tens column
is 0,1,2,3, or 4, then round
down to the lesser hundred.
Sorry.
Look at the numbers in the tens column. Do
they cause the number to be rounded to the
lesser hundred or the greater hundred?
Click here to try again.
Yes!! You are correct. When a number has a
0, 1, 2, 3, or 4 in the tens column you round to
the lesser hundred! For example 429 rounds
to 400.
Click here to continue
Look at these examples. Try to
determine what the rule is for
rounding to the nearest hundred.
563 rounds to 600
179 rounds to 200
499 rounds to 500
381 rounds to 400
262 rounds to 300
958 rounds to 1000
674 rounds to 700
755 rounds to 800
Choose the rule:
A
B
If the number in the tens
column is 5, 6, 7, 8, or 9 then
round up to the greater
hundred.
If the number in the tens
column is 5, 6, 7, 8, or 9 then
round down to the lesser
hundred.
Sorry.
Look at the numbers in the tens column. Do
they cause the number to be rounded to the
lesser hundred or the greater hundred?
Click here to try again
• Yes!! You are correct. When a
number has a 5, 6, 7, 8, or 9 in
the tens column you round to
the greater hundred!
Click here to continue
Remember the example of the car going over the hill.
When rounding to the nearest hundred, any number that ends in 49 or
less will cause the car to roll back to the lesser hundred and any
number that ends in 50 or greater, will cause the car to roll up to the
greater hundred.
If you round 720 to the nearest ten, then your choices are either round
back to 700 or up to 800. If the car goes up to 720 and stops, then it
will roll back to 700.
Click here to continue
720 rounds to 700
740
730
720
750
760
770
780
710
700
790
800
Here is another example. If you round 360 to the nearest hundred,
then your choices are either round back to 300 or up to 400. If the car
goes to 360 and stops, then it will roll to 400.
Click here to continue
360 rounds to 400
340
330
320
350
360
370
380
310
300
390
400
Now it’s your turn to round to the
nearest hundred!
Round 236
A
200
B
300
C
400
Sorry.
Remember the rules:
1. If the number you are rounding is
followed by a 0, 1, 2, 3, or 4, then
round down .
2. If the number you are rounding is
followed by a 5, 6, 7, 8, or 9, then
round up.
Click here to try again
Yes!! You are correct.
Click here to continue
Round to the nearest hundred.
Round 581
A
500
B
550
C
600
Sorry.
Remember the rules:
1. If the number you are rounding is
followed by a 0, 1, 2, 3, or 4, then
round down .
2. If the number you are rounding is
followed by a 5, 6, 7, 8, or9, then
round up.
Click here to try again
Yes!! You are correct.
Click here to continue
Round to the nearest hundred.
Round 749
A
600
B
700
C
800
Sorry.
Remember the rules:
1. If the number you are rounding is
followed by a 0, 1, 2, 3, or 4, then
round down .
2. If the number you are rounding is
followed by a 5, 6, 7, 8, or9, then
round up.
Click here to try again
Yes!! You are correct.
Click here to continue
Last you will learn to round to
the nearest thousand!
When you round to the nearest thousand
you are estimating which thousand the
number is closest to.
Click here to continue
Rounding to the Nearest
Thousand
Posen 2600 miles
You estimate which thousand the number you are
rounding is closest to. If you saw a road sign that said
Posen was 2600 miles away, then you could say that
Posen is about 3000 miles away.
2000 2100 2200 2300 2400 2500 2600 2700 2800 2900 3000
2600 rounds to 3000
2600 is closer to 3000 than
2000
continue
Look at these examples. Try to
determine what the rule is for
rounding to the nearest thousand.
2456 rounds to 2000
5302 rounds to 5000
3289 rounds to 3000
7367 rounds to 7000
8422 rounds to 8000
7056 rounds to 7000
1245 rounds to 1000
9135 rounds to 9000
Choose the rule:
A
B
If the number in the hundreds
column is 0, 1, 2, 3, or 4 then
round up to the greater
thousand.
If the number in the hundreds
column is 0,1,2,3, or 4, then
round down to the lesser
thousand.
Sorry.
Look at the numbers in the hundreds column.
Do they cause the number to be rounded to
the lesser thousand or the greater thousand?
Click here to try again.
Yes!! You are correct. When a number has a
0, 1, 2, 3, or 4 in the hundreds column you
round to the lesser thousand! For example
8368 rounds to 8000.
Click here to continue
Look at these examples. Try to
determine what the rule is for
rounding to the nearest thousand.
4589 rounds to 5000
6900 rounds to 7000
3682 rounds to 4000
2766 rounds to 3000
1805 rounds to 2000
5693 rounds to 6000
8954 rounds to 9000
7725 rounds to 8000
Choose the rule:
A
If the number in the hundreds column
is 5, 6, 7, 8, or 9 then round up to
the greater thousand.
B
If the number in the hundreds column
is 5, 6, 7, 8, or 9 then round down
to the lesser thousand.
Sorry.
Look at the numbers in the hundreds column.
Do they cause the number to be rounded to
the lesser thousand or the greater thousand?
Click here to try again
• Yes!! You are correct. When a
number has a 5, 6, 7, 8, or 9 in
the hundreds column you round
to the greater thousand!
Click here to continue
Let’s look at the hill again. If you are to round 6300 to the nearest
thousand, then your choices are either round back to 6000 or up to
7000. If the car goes up to 6300 and stops, then it will roll back to 6000.
6300 rounds to 6000
Click here to continue
6400
6300
6200
6500
6600
6700
6800
6100
6000
6900
7000
Here is another example. If you are to round 2900 to the nearest
thousand, then your choices are either round back to 2000 or up to
3000. If the car goes to 2900 and stops, then it will roll to 3000.
2900 rounds to 3000
Click here to continue
2400
2300
2200
2500
2600
2700
2800
2100
2900
2000
3000
Now it’s your turn to round to the
nearest thousand!
Round 5798
A
5800
B
6000
C
5000
Sorry.
Remember the rules:
1. If the number you are rounding is
followed by a 0, 1, 2, 3, or 4, then
round down .
2. If the number you are rounding is
followed by a 5, 6, 7, 8, or9, then
round up.
Click here to try again
Yes!! You are correct.
Click here to continue
Now it’s your turn to round to the
nearest thousand!
Round 2045
A
2000
B
2050
C
2100
Sorry.
Remember the rules:
1. If the number you are rounding is
followed by a 0, 1, 2, 3, or 4, then
round down .
2. If the number you are rounding is
followed by a 5, 6, 7, 8, or9, then
round up.
Click here to try again
Yes!! You are correct.
Click here to continue
Now it’s your turn to round to the
nearest thousand!
Round 9430
A
8430
B
8400
C
9000
Sorry.
Remember the rules:
1. If the number you are rounding is
followed by a 0, 1, 2, 3, or 4, then
round down .
2. If the number you are rounding is
followed by a 5, 6, 7, 8, or 9, then
round up.
Click here to try again
Yes!! You are correct.
Click here to continue
For more practice rounding to the nearest ten click the link!
http://www.aaamath.com/g4-32-round10.html#section2
For more practice rounding to the nearest hundred click the link!
http://www.aaamath.com/g4-32-round100.html#section2
For more practice rounding to the nearest thousand click the link!
http://www.aaamath.com/g41c-round1000.html#section2
You’re Finished!!
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