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Transcript
Today we will learn…
2-5: Rounding
how to round 2 and 3 digit
numbers to the tens or
hundreds place.
Vocabulary
• Rounding
Rounding Strategies
1. One way to round numbers is to think
about a number line.
Rounding on number line video
2. The second way to round is to circle the
place value and look to see if the number to
the right is weak or powerful.
Rounding Rap Video
Rounding
When rounding remember the weak
and powerful numbers……
Weak
0, 1, 2, 3, 4
Powerful
5, 6, 7, 8, 9
Remember this…
1. Circle the place value
2. Look next door.
3. Does it have power ? (5, 6, 7, 8, 9)
Then go up
one more!
4. If it is weak, it stays the same.
That is part of the rounding game!
Now Let’s Practice…..
Round the number to the nearest tens place
value.
9 0
789
1st Circle the place value
2nd draw an arrow next door
3rd Does the 9 have power?
4th Yes! –The number that is underlined goes up
one more!
5th Everything after the underlined digit
becomes a 0 What’s your rounded number?
790
Here’s another….
Round the number to the nearest tens place value.
462
1st Circle the place value
2nd draw an arrow next door
3rd Does the 2 have power?
4th No! –The number that is underlined stays the same!
5th Everything after the underlined digit becomes a 0
What’s your rounded number? ….
460
Round the number to the nearest tens place
value.
45
1st Circle the place value
2nd draw an arrow next door
3rd Does the 5 have power?
4th Yes! –The number that is underlined goes
up one more!
5th Everything after the underlined digit
becomes a 0 What’s your rounded
number? ….
50
Round the number to the nearest hundreds
place value.
762
1st Circle the place value
2nd draw an arrow next door
3rd Does the 6 have power?
4th Yes! –The number that is underlined goes
up one more!
5th Everything after the underlined digit
becomes a 0 What’s your rounded
number? ….
800
Round the number to the nearest hundreds
place value.
402
1st Circle the place value
2nd draw an arrow next door
3rd Does the 0 have power?
4th No! –The number that is underlined stays
the same!
5th Everything after the underlined digit
becomes a 0 What’s your rounded
number? ….
400
Ready for a challenge?
Round the number to the nearest hundreds
place value.
5,633
1st Circle the place value
2nd draw an arrow next door
3rd Does the 3 have power?
4th NO! –The number that is underlined stays
the same!
5th Everything after the underlined digit
becomes a 0 What’s your rounded
number? ….
5,600
Sun-Yi estimated 270 + 146
and got 300. Is her estimate
reasonable? Explain using
rounding.
Carefully read the
problem.
Underline the question.
[Bracket] important
words and numbers.
Eliminate unnecessary
information.
Solve and check your
work.
Natalie has 138 DVD’s and 419
CD’s. About how many DVD’s
and CD’s does she have
altogether?
Carefully read the
problem.
Underline the question.
[Bracket] important
words and numbers.
Eliminate unnecessary
information.
Solve and check your
work.