Transcript Rounding Whole Numbers Power Point

Using RAP to
Round Whole
Numbers
Created by: Libby Maccani
Educational Concern
BIG IDEA:
 Estimation: Numbers can be approximated by
numbers that are close. Numerical calculations
can be approximated by replacing numbers with
other numbers that are close and easy to
compute with mentally.
 Mathematical Processes: Doing mathematics
involves a variety of processes including problem
solving, reasoning, communicating, connecting,
and representing.
Educational Concern
 The rounding process is based on knowing the
multiples of 10, 100, and so on.
 Rounding is a process of finding the multiple of
10, 100, or 1,000 closest to a given number.
 Objective for this lesson: Students round 2-, 3-
and 4- digit whole numbers to the nearest ten,
hundred, or thousand by rounding rap and place
value.
Curriculum Standards
Number Sense
1.0 Students understand the place value of whole
numbers:
1.4 Round off numbers to 10,000 to the nearest
ten, hundred, and thousand.
Review
 Rounding: To replace a number with a number
that tells about how many to the nearest ten,
hundred, thousand, and so on.
 Example:
20 21 22 23 24 25 26 27 28 29 30
 27 is closer to 30, so we would round it to 30!
 Place value: The value given to the place a digit
has in a number.
Rounding Rap
ARE YOU READY TO
RAP?
FOLLOW ALONG WITH THIS
RAP AND YOU WILL BE A
PRO AT ROUNDING!!
WE ARE GOING TO ROUND
2,372 TO THE NEAREST
HUNDRED…
Find the place value and
circle that digit
We are rounding to the hundreds place,
so we are going to circle the number in the hundreds place.
2,372
Move to the right,
Underline get it
We are going to look to the right of the number we have circled.
The place value next to the hundreds place is the tens place.
We are going to underline the number in the tens place.
2,372
0 through 4,
Circle stays the same
We underlined the 7 in the tens place.
If the number we underlined is 0, 1, 2, 3, 0r 4,
we leave the number in the circle alone.
The number we underlined is a 7,
so this step does not apply to us.
2,372
5 through 9,
Add 1 in this game
We underlined the 7 in the tens place.
If the number we underlined is 5, 6, 7, 8, 0r 9
we add 1 to the number in the circle.
The number we underlined is a 7,
so we add 1 to the number in the circle.
3+1=4
2,472
Now flex your muscles like a hero,
Digits to the right change to ZERO
All the digits to the right of the number in the circle,
change to ZERO.
The tens place and the ones place
are to the RIGHT of the hundreds place.
So, the 7 and the 2 both change to ZERO.
2,400
All other digits remain the same,
YO! You’re a winner at the rounding game!
The other digits, or the digits to the right of the circle,
STAY THE SAME.
We do not change those digits or forget to put those digits in the final answer.
So in this number, we leave the 2 in the thousands place the same.
2,400
We just rounded 2,372 to the nearest hundred.
The nearest hundred is 2,400.
x
2,300
2,350
2,400
2,372
2,372 is closer to 2,400 rather than 2,300.
Rounding 534 to the nearest TEN
534
Rounding 6,721 to the nearest THOUSAND
6,721
Practice
Use the
Rounding Rap
to round
3,526 to the
nearest TEN.
 Find the place value and circle





that digit.
Move to the right, underline
get it.
0 through 4, circle stays the
same.
5 through 9, add one in this
game.
Now flex your muscles like a
hero, digits to the right change
to zero.
All other digits remain the
same, Yo! You’re a winner at
the rounding game!
What did you get when you rounded
3,526 to the nearest TEN?
3,520
30
3,530
3,500
You’re Right!
GREAT JOB!
Next
Proble
m
Try Again!
You Can Do It!
Back to
Question
Round 5,654 to the nearest
THOUSAND
5,700
5,000
5,650
6,000
You’re Right!
GREAT JOB!
Next
Slide
Try Again!
You Can Do It!
Back to
Proble
m
Things to think about…
 When do we use rounding in our everyday lives?
 Why do we round numbers?
 When we round whole numbers, what are we
actually doing?
Read this article: Real-life Life Rounding Experience
Challenge!
 Who thinks their group has some great ideas?
 Who wants to present their information to the
class tomorrow?
 Decide as a group which ideas are the best
 Plan a way to share your thoughts with the class
Tomorrow we will hear from the groups and learn
more about the importance of rounding!