Madeline estimated the product of 3.56 and 8.3 below.

(3.56)(8.3)=4*9=36

How does the estimate compare to the exact product?
A.The estimate is high because both factors are rounded down.
B.The estimate is low because both factors are rounded down.
C.The estimate is high because both factors are rounded up.
D.The estimate is low because both factors are rounded up.


Gasoline costs $3.65 a gallon. Which is an estimated cost of 14.2 gallons of gasoline?
A.$18
B.$30
C.$40
D.$56

Stu is laying brick down to make a patio. He plans for the patio to be 12.5 feet by 18.3 feet. He orders enough brick for 247 square feet. Which statement about the amount of brick is correct?
A.Stu estimated correctly by rounding up. He ordered enough brick. The exact area is 228.75 square feet.
B.Stu estimated correctly by rounding down. He ordered enough brick. The exact area is 228.75 square feet.
C.Stu did not estimate correctly by rounding up. He did not order enough brick. The exact area is 228.75 square feet.
D.Stu did not estimate correctly by rounding down. He did not order enough brick. The exact area is 228.75 square feet.


Velvet fabric costs $11.49 a yard. Yvette buys 9.3 yards. Yvette’s estimated cost of the velvet is
A.$20.
B.$99.
C.$104.
D.$120.

Eoin plans to purchase 6.50 pounds of cheese that costs $4.75 per pound. He used the following steps to estimate the cost.

Step 1: Round 6.50 pounds up to 7.
Step 2: Round $4.75 up to $5.00.
Step 3: Multiply 5 by 7 to get 35.
Step 4: Conclude that the cost will be just over $35.00.

In which step does Eoin make a mistake?
A.In step 1, he should have rounded the weight down to 6 pounds.
B.In step 2, he should have rounded the cost down to $4.00.
C.In step 3, he chose the wrong operation to calculate cost.
D.In step 4, he should have concluded the cost would be under $35.00

Round steak costs $6.95 per pound. Sara wants to buy 9.5 pounds of round steak which she estimates will cost $54. Which statement about Sara’s estimate is true?
A.Sarah rounded $6.95 and 9.5 up. $54 is enough money to buy the steak.
B.Sarah incorrectly multiplied 9 and 6. Her estimate should be $63.
C.Sarah rounded 9.5 up to 10. Her estimate of $54 is too high.
D.Sarah rounded $6.95 and 9.5 down. Her estimate of $54 is too low.

Manuel buys 7.9 pounds of strawberries. Each pound costs $3.89. Which expression gives the best estimate of the cost of the strawberries?
A.(8)($4)
B.(7)($4)
C.(8)($3)
D.(7)($3)

Kerrie is tiling the floor of a kitchen. The kitchen floor measures 11.3 feet by 9.25 feet. She orders enough tiles for 99 square feet. Which statement about the amount of tiles is correct?
A.Kerrie estimated correctly by rounding down. She has enough tile. The exact area is 104.5 square feet.
B.Kerrie estimated correctly by rounding up. She has enough tile. The exact area is 104.5 square feet.
C.Kerrie did not estimate correctly by rounding up. She does not have enough tile. The exact area is 104.5 square feet.
D.Kerrie did not estimate correctly by rounding down. She does not have enough tile. The exact area is 104.5 square feet.

Respuesta :

The estimate is low because both factors are rounded up.

1.

C. The estimate is high because both factors are rounded up.

3.56 and 8.3 is rounded as 4*9. Rather it should have been rounded up like = 3.56 to 4 and 8.3 to 8 ; making [tex]4\times8[/tex]=32

2.

Gasoline costs $3.65 a gallon. Round this to $4. To find the estimated cost of 14.2 gallons of gasoline, round this to 14.

So, cost becomes = [tex]14\times4[/tex] = $56

Option D is correct.

3.

Stu plans for the patio to be 12.5 feet by 18.3 feet.

Actual area becomes = [tex]12.5\times18.3[/tex] = 228.75 square feet

He orders enough brick for 247 square feet. Means he rounded off 12.5 to 13 and 18.3 to 19. Making [tex]13\times19=247[/tex] sq feet.

The correct option is A. Stu estimated correctly by rounding up. He ordered enough brick. The exact area is 228.75 square feet.

4.

Velvet fabric costs $11.49 a yard. Yvette buys 9.3 yards

Rounding 11.49 to 11.50 and 9.3 to 9, we get [tex]11.50\times9=103.5[/tex] or $104.

Option C is correct.

5.

As the values are rounded up and not down, the cost will be under $35. So, correct answer is option D .In step 4, he should have concluded the cost would be under $35.00

6.

$6.95 is rounded down to 6 and 9.5 is down to 9. This gives 54 which is too low. Rather it should be rounded up like $6.95 to 7 and 9.5 to 10 making it 7*10=70. So, option D is correct.

D.Sarah rounded $6.95 and 9.5 down. Her estimate of $54 is too low.

7.

Manuel buys 7.9 pounds of strawberries. Each pound costs $3.89.

Now rounding 7.9 to 8 and 3.89 to 4 , we get the best estimate. So, option A 8*4 is correct.

8.

The kitchen floor measures 11.3 feet by 9.25 feet.

The actual area is = [tex]11.3\times9.25=104.525[/tex] sq feet. But Kerrie had ordered tiles for only 99 sq feet which is very less. So, she estimated wrongly by rounding down the values. So, the correct answer is option D.

D. Kerrie did not estimate correctly by rounding down. She does not have enough tile. The exact area is 104.5 square feet.