Rounding Whole Numbers And

Estimation

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This slide show has been created by Heather Hoene at Barrington Elementary School.

These activities will address the following Hazelwood Objectives for fifth grade.

Explain math concepts and problem solutions orally and in writing.

Understand concept of rounding wholenumbers and estimation.

Apply problem-solving strategies toreal-world problems.

Whenever you see this picture, you willneed to write the answer in your journal.

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68,000

68,242

69,000

The population of the Sioux Reservation was 68,242. To the nearest thousand, what was the population?

Explain why you think this.

68,242 is between 68,000 and 69,000, but it is closer to 68,000.

1) 28,458 2) 28,925 3) 28,512

What digit(s) can help you round to the nearest thousand?

Round to the nearest thousand.

1) 28,458 2) 28,925 3) 28,512

What digit(s) can help you round to the nearest thousand?

Round to the nearest thousand.

28,000 29,000 29,000

Explain why you think this.

Round 73,852 to the nearest

1. Ten-thousand.

2. Thousand.

3. Hundred.

4. Ten.

70,000

74,000

73,900

73,850

Explain why you think this.

The Smith family wants to buy a truck that costs$18,530 and camping trailer that costs $8,427.

Estimate the total cost of the truck and thecamping trailer.

18,530 8,427

Round up Round down

19,000 + 8,000 = 27,000

The total cost is about $27,000.Figure the exact cost. What is the difference?

$18,530

+ $8,427

The exact cost is $26,957

$27,000

-$26,957

It is a difference of $43.00

Your class is planning on making a pizza. Below is a list of everything you will need to buy. About how much money does your class need to bring to the store?

1 8 oz. bag of mozzarella cheese $8.57 1 green pepper $0.961 medium onion $0.331 can of tomato sauce $4.78 1 2 oz. can of mushrooms $2.331 package of pizza dough $6.99

Estimate!

1 8 oz. Bag of mozzarella cheese $8.571 green pepper $0.961 medium onion $0.331 can of tomato sauce $4.781 2 oz. Can of mushrooms $2.331 package of pizza dough $6.99

$9.00 $1.00 $0.50 $5.00 $2.50+ $7.00 $ 25.00.

Your class will need about

*There are different ways you can estimate the totalcost. Did you come up with any other ways?

Estimate the number of bricks used to build this portion of a chimney.

Answers will vary!

Estimate the number of bricks used to build this portion of a chimney.

* 15 Bricks tall* About 4 bricks long 15 x 4 x 2 = 120 bricks* About 2 bricks wide approximately

The end.