Week #27 Bell ringers and quiz 8 th grade math. Bell Ringer Monday Four figures have the following dimensions: Rectangular prism: l=2 in; w=4 in; h=7.

Week #27 Bell ringers and quiz

8th grade math

Bell RingerMonday

Four figures have the following dimensions:

Rectangular prism: l=2 in; w=4 in; h=7 inCylinder: r=4 in; h=6 inCone: r=4 in; h=6 inRectangular pyramid: l=2 in; w=4 in; h=7

in1. What is the probability that a figure chosen

at random will have a volume greater than 150 cubic inches?

2. Two figures are pulled one at a time. After you pull the first time, you do not replace. What is the probability both figures will have a volume less than 125 cubic inches?

3. Calculate the mean.

Rectangular prism: l=2 in; w=4 in; h=7 inCylinder: r=4 in; h=6 inCone: r=4 in; h=6 inRectangular pyramid: l=2 in; w=4 in; h=7 in

356

)7)(4)(2(

:rPrismRectangula

inV

VlwhV

3

2

44.301

)6)(16)(14.3(

:Cylinder

inV

VhrV

3

3218

)7)(4)(2(3131

:rPyramidRectangula

inV

V

lwhV

3

2

48.100

)6)(16)(14.3(3131

:Cone

inV

V

hrV

Rectangular prism: l=2 in; w=4 in; h=7 in V=56in3

Cylinder: r=4 in; h=6 in V=301.44in3

Cone: r=4 in; h=6 in V=18.67in3

Rectangular pyramid: l=2 in; w=4 in; h=7 in V=100.48in3

1. What is the probability that a figure chosen at random will have a volume greater than 150 cubic inches?

2. Two figures are pulled one at a time. After you pull the first time, you do not replace. What is the probability both figures will have a volume less than 125 cubic inches?

%2541)150( orP

21

126

32

43)1252( P

Rectangular prism: l=2 in; w=4 in; h=7 in V=56in3

Cylinder: r=4 in; h=6 in V=301.64in3

Cone: r=4 in; h=6 in V=18.67in3

Rectangular pyramid: l=2 in; w=4 in; h=7 in V=100.48in3

3. Calculate the mean.4)48.10067.1864.30156(

320.1194

79.476 in

QuizMonday

Roderick is building a model of an actual airplane with a length of 20 feet. What other information is necessary in order to find x, the length of the model airplane?

F The ratio of the length of the model airplane’s tail to the length of its wingG The speed of the model airplaneH The scale factor usedJ The model airplane’s wingspan

What information is needed to find x?

Anything involving dilations must have a scale factor. If one dimension is known, the dimension of the similar figure can be found by multiplying by the scale factor.

Roderick is building a model of an actual airplane with a length of 20 feet. What other information is necessary in order to find x, the length of the model airplane?

The scale factor is needed to find x.

Actual length = 20 feetx = model lengthDilation

Reductionsor tsEnlargemen:Dilations

factor scale by theMultiply

factor. scale by the gmultiplyinby found becan length model the

known, islength actual theSince:H

1. Calculate the area of each triangle.2. Calculate the perimeter of each triangle.3. Are the figures similar?4. Calculate the probability of randomly

picking a triangle and it is a right triangle.

3

4

58

6

11

A B

Bell Ringer Tuesday

1. Calculate the area of each triangle.

2. Calculate the perimeter of each triangle.

3

4

58

6

11

A B

262

122

)4(3 unitsAa 224

248

2)8(6 unitsAb

unitsPaPa

12543

unitsPaPb

251186

3. Are the figures similar?

3

4

58

6

11

A B

115

84

63: NO

similar.not are figures theso factor, scale same

thehavenot do sides The

3

4

5A

32+42=52

9+16=2525=25Right Triangle

8

6

11

B

Not Right Triangle

62+82=11236+64=12

1100 ≠ 121

4. Calculate the probability of randomly picking a triangle and it is a right triangle.

%5021:)( orRightP

QuizTuesday

A pattern of equations is shown below.1% of 800 = 82% of 400 = 84% of 200 = 88% of 100 = 816% of 50 = 8

Which statement best describes this pattern of equations?F. When the percent is doubled and the other number is halved, the answer is 8.G. When the percent is doubled and the other number is doubled, the answer is 8.H. When the percent is increased by 2 and the other number remains the same, the answer is 8.J. When the percent remains the same and the other number is increased by 2, the answer is 8.

Which statement is the best description of the pattern?

I found the pattern involving the percents. All the percents were doubled. I found the patter involving the whole numbers. All whole numbers were cut in half. They all were equivalent to 8.

A pattern of equations is shown below. 1% of 800 = 8; 2% of 400 = 8; 4% of 200 = 8; 8% of 100 = 8; 16% of 50 = 8. Which statement best describes this pattern of equations?

Statement F is the best description of the pattern.

1% of 800 = 82% of 400 = 84% of 200 = 88% of 100 = 816% of 50 = 8

%16)2(88)2(44)2(22)2(1

:

Double

Percent

HalfWhole

Whole

502100100220020024004002800

:#

8AllEqual

StatementF

Bell RingerWednesday

There are 10 marbles in a bag. 4 are red, 2 blue, 1 yellow, and 3 green. You are going to pick two marbles one at a time. After you pick a marble, you do not replace it. (Treat each question independent of the other ones).

1. P(red and green)2. P(yellow and blue)3. P(2 blues)4. P(2 yellows)5. Calculate the mode6. What percent are green?

There are 10 marbles in a bag. 4 are red, 2 blue, 1 yellow, and 3 green. You are going to pick two marbles one at a time. After you pick a marble, you do not replace it.

1. P(red and green)

2. P(yellow and blue)

3. P(2 blues)

152

9012

93

104)&( GRP

451

902

92

101)&( BYP

451

902

91

102)&( BBP

There are 10 marbles in a bag. 4 are red, 2 blue, 1 yellow, and 3 green. You are going to pick two marbles one at a time. After you pick a marble, you do not replace it.

4. P(2 yellows)

5. Calculate the mode

6. What percent are green?

%0900

90

101)&( YYP

greenyellowbluered 3;1;2;4dMode Re

100%

wholepart

100%

1010103

%30

QuizWednesday

Trace paid Dalton $15.50 for a combination of 15 baseball and football cards. The

baseball cards were $1.50 each, and the football cards were $0.50 each. How much

did Trace spend on the football cards?

How much was spent on football cards?

I guessed and checked to find the right combination. I started with 10 baseball cards. When I multiplied that by $1.50, I got $15. I would still need 5 football cards, so 10 baseball cards is too much. I multiplied the number of cards by the price per card. The right combination is 8 baseball and 7 football.

Trace paid Dalton $15.50 for a combination of 15 baseball and football cards. The baseball cards were $1.50 each, and the football cards were $0.50 each.

How much did Trace spend on the football cards?

$3.50 is spent on football cards.

Spent $15.5015 total cardsBaseball $1.50Football $0.50

15$)50.1(10:10 Baseball

50.12$:00.5$)50(.10:10

50.7$)50.1(5:5

TotalFootballBaseball

50.15$:50.3$)50(.7:7

00.12$)50.1(8:8

TotalFootballBaseball

50.3$

Bell RingerThursday

Sheila made a scale drawing of a room. The actual room has a width of 16 feet and a length of 24 feet. Her drawing has a length of 3 feet.

1. What type of dilation occurred?2. Calculate the scale factor.3. What is the width, in inches, of the scale

drawing of the room? 4. Calculate the area of the scale drawing of the

room.5. Based on the dilation, how is the perimeter

affected?


1. What type of dilation occurred?

2. Calculate the scale factor.

Reduction

lw

lw

32416

lw3

8124

8116

81


3. What is the width, in inches, of the scale drawing of the room?

4. Calculate the area of the scale drawing of the room.

lw

32

8124

8116

lwA26

)2(3

ftA

A

infeet 242

Sheila made a scale drawing of a room. The actual room has a width of 16 feet and a length of 24 feet. Her drawing has a length of 3 ft.

5. Based on the dilation, how is the perimeter affected?

ftPPPOriginalP

804832

)24(2)16(2:

ftPPPNewP

1046

)2(2)3(2:

81

8010

originalnew

perimeter. original theof size the1/8

isperimeter new The

QuizThursday

A water tank contains 2,500 gallons. A faucet attached to the tank releases water at a constant rate of 5 gallons per minute. If the faucet is left open for 1 hour and no

other water is released, which equation can be used to find r, the number of gallons of

water remaining in the tank?

A. r = 2,500 ÷ 5B. r = 2,500 – 60C. r = 2,500 – 60(5)D. r = 2,500 ÷ 60(5)

Which equation can be used?

Since 5 gallons of water is released per minute, I multiplied 5 by the number of minutes the water was released. It was released for one hour, so that is 60 minutes. To find the number of gallons left, I subtracted the water loss from the volume of the tank.

A water tank contains 2,500 gallons. A faucet attached to the tank releases water at a constant rate of 5 gallons per minute.

If the faucet is left open for 1 hour and no other water is released, which equation can be used to find r, the number of

gallons of water remaining in the tank?

Equation C can be used to find the number of gallons left.

Holds 2500 gallonsReleases 5 gallons per minuteOpen for 1 hourr = number of gallons in tank

gallonsumeCurrentVol 2500:

5(60)hour 1for 5gal/min :WaterLoss

EquationC

LossVolume)60(52500

hour1min60

Week #27 Bell ringers and quiz 8 th grade math. Bell Ringer Monday Four figures have the following dimensions: Rectangular prism: l=2 in; w=4 in; h=7.

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