Transcript Rounding Powerpoint

rd
3
Grade
Rounding
By Monica Yuskaitis
California Standard Addressed
Number
Sense
Third
Grade
1.4 Round off numbers to 10,000
to the nearest ten, hundred, and
thousand.
Copyright © 2000 by Monica Yuskaitis
Objectives
 To
be able to round numbers to the
nearest ten
 To be able to round numbers to the
nearest hundred
 To be able to round numbers to the
nearest thousand
Copyright © 2000 by Monica Yuskaitis
Vocabulary

Round – to replace an exact number
by another that is close to it in value
and easier to use. For example, 52,
rounded to the nearest ten is 50.
Copyright © 2000 by Monica Yuskaitis
Use rounding
• When the question asks you
to estimate.
• When the question asks
“about how many”…?
• When an exact answer isn’t
possible.
• When an answer is difficult
to obtain.
Copyright © 2000 by Monica Yuskaitis
Memorize this Poem
Find your number.
Look right next door.
4 or less just ignore.
5 or more, add 1 more.
Copyright © 2000 by Monica Yuskaitis
Round this number to the nearest
ten.
Find your number.
47
Circle the number in the tens
place.
Copyright © 2000 by Monica Yuskaitis
Round this number to the nearest
ten.
Look right next door.
47
Draw an arrow to the right of the
number.
Copyright © 2000 by Monica Yuskaitis
Round this number to the nearest
ten.
4 or less, just ignore.
47
7 is larger than 4 so go to the
next line of the poem.
Copyright © 2000 by Monica Yuskaitis
Round this number to the nearest
ten.
5 or more, add 1 more.
+1
47
Add 1 to the 4.
Copyright © 2000 by Monica Yuskaitis
Round this number to the nearest
ten.
5 or more, add 1 more.
50
After adding 1 to the 4, all the numbers
to the right of the 5 become 0’s.
Copyright © 2000 by Monica Yuskaitis
The Answer
4 7 rounded to the
nearest tens place is
50
40
47
50
Note 47 is closer to 50 on the number line.
Copyright © 2000 by Monica Yuskaitis
Round this number to the nearest
hundred.
Find your number.
986
Circle the number in the hundreds
place.
Copyright © 2000 by Monica Yuskaitis
Round this number to the nearest
hundred.
Look right next door.
986
Draw an arrow to the right of the
number.
Copyright © 2000 by Monica Yuskaitis
Round this number to the nearest
hundred.
4 or less, just ignore.
986
8 is larger than 4 so go to the
next line of the poem.
Copyright © 2000 by Monica Yuskaitis
Round this number to the nearest
hundred.
5 or more, add 1 more.
+1
986
Add 1 to the 9.
Copyright © 2000 by Monica Yuskaitis
Round this number to the nearest
hundred.
5 or more, add 1 more.
1, 0 0 0
After adding 1 to the 9, all the numbers
to the right of the 10 become 0’s.
Copyright © 2000 by Monica Yuskaitis
The Answer
986 rounded to the
nearest hundreds place is
900
1, 0 0 0
986 1,000
Note 986 is closer to 1,000 on the number
line.
Copyright © 2000 by Monica Yuskaitis
Round this number to the nearest
thousand.
Find your number.
3 5, 3 2 7
Circle the number in the thousands
place.
Copyright © 2000 by Monica Yuskaitis
Round this number to the nearest
thousand.
Look right next door.
3 5, 3 2 7
Draw an arrow to the right of the
number.
Copyright © 2000 by Monica Yuskaitis
Round this number to the nearest
thousand.
4 or less, just ignore.
3 5, 3 2 7
Since 3 is less than 4 we do not change
the 5.
Copyright © 2000 by Monica Yuskaitis
Round this number to the nearest
thousand.
4 or less, just ignore.
3 5, 0 0 0
Change the numbers to left of 5 to 0’s.
Copyright © 2000 by Monica Yuskaitis
The Answer
35,327 rounded to the
nearest thousand is
3 5, 0 0 0
35,000
35,327
36,000
Note 35,327 is closer to 35,000 on the
number line than to 36,000.
Copyright © 2000 by Monica Yuskaitis
Round these numbers to the
nearest ten.
139
140
45
50
282
280
97
100
Copyright © 2000 by Monica Yuskaitis
Round these numbers to the
nearest hundred.
2, 1 3 9
2, 1 0 0
1 9, 7 4 5
1 9, 7 0 0
282
300
3, 1 9 7
3, 2 0 0
Copyright © 2000 by Monica Yuskaitis
Round these numbers to the
nearest thousand.
2, 8 3 9
3, 0 0 0
1 9, 4 4 5
1 9, 0 0 0
8, 9 8 2
9, 0 0 0
4 3,1 9 7
4 3, 0 0 0
Copyright © 2000 by Monica Yuskaitis
Credits
Illustrations from:
 Clipart
from ClickArt 125,000 Deluxe
Image Pak, T/Maker Co., Broderbund
Software, Inc.
Copyright © 2000 by Monica Yuskaitis