week 24 bell ringers & quiz
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Week 24 Bell Ringers & Quiz. 8 th grade math. Bell Ringer Tuesday. 1. Calculate the number of cubic inches each figure can hold. Calculate the mean of the volumes. Calculate the range of the volumes. 4. If the dimensions of every figure are doubled, how are the volumes affected?. 2 in. - PowerPoint PPT PresentationTRANSCRIPT
Week 24 Bell Ringers & Quiz
8th grade math
Bell RingerTuesday
1. Calculate the number of cubic inches each figure can hold.2.Calculate the mean of the volumes.3.Calculate the range of the volumes.4. If the dimensions of every figure are doubled, how are the volumes affected?
2 in
1 in
3 in
2 in
1 in
4 in
5 in
1 in
1 in
1. Calculate the number of cubic inches each figure can hold.
2 in
1 in
3 in
2 in
1 in
4 in
5 in
1 in
1 in
lwhV )2)(1(3V
36inV
lwhV )4)(1(2V
38inV
lwhV )1)(1(5V
35inV
36in 38in35in
2. Calculate the mean of the volumes.3. Calculate the range of the volumes.
2 in
1 in
3 in
2 in
1 in
4 in
5 in
1 in
1 in
3
)586(:mean
3
19 3
3
16 in
3358: inRange
36in 38in35in
4. If the dimensions of every figure are doubled, how are the volumes affected?
2 in
1 in
3 in
2 in
1 in
4 in
5 in
1 in
1 in
2:rScaleFacto 823
volumes.original n thelarger tha
times8 are volumesnew The
36in 38in35in
QuizTuesday
The first triangle is dilated to create the second triangle. What is the perimeter of the dilated triangle?
6 cm
5 cm2.5 cmx cm
7 cm
3 cm
What is the perimeter of the new triangle?
I found the scale factor used by dividing the new side by the original side. I multiplied the other dimension by the scale factor to get the missing dimension. I added the three sides together to get the perimeter.
The first triangle is dilated to create the second triangle. What is the perimeter of the dilated triangle?
The new perimeter is 9 cm.
Reduction1st: 5 cm, 6 cm, 7 cm2nd: 2.5 cm, 3 cm, x cm
5.6
3
Original
New
cm5.3)5(.7
cmP
P
9
35.25.3
Bell RingerWednesday
You go on a hike. You hike 3 miles to the east and 4 miles north.
1. What is the quickest route back to camp?
2. How much quicker is this than hiking back the way you came?
HINT: draw a picture!!
You go on a hike. You hike 3 miles to the east and 4 miles north.
1. What is the quickest route back to camp?
3 miles
4 miles
222 43 c2169 c
225 c225 c
milesc 5
5 miles
You go on a hike. You hike 3 miles to the east and 4 miles north.
2. How much quicker is this than hiking back the way you came?
3 miles
4 miles
milesmilesmiles 743
5 miles
rmilesFastemilesmiles 257
QuizWednesday
Out of 50 tourists, 30 tourists bought food from the ocean-side concession
stand. What percentage of tourists did not buy food from the concession
stand?
What percent did not buy food?
To find the percent that did not buy food, I subtracted the total that did buy food from the total number of tourists. I set up a percent proportion, using the amount that did not buy food. I multiplied by a scale factor of 2.
Out of 50 tourists, 30 tourists bought food from the ocean-side concession stand. What percentage of tourists did not buy food from the concession stand?
Forty percent of the tourists did not buy food.
50 tourists30 bought20 did not buy
100
%
whole
part
100
%
50
20
total
Not
100
40
250
220
total
Not
%40
Bell RingerThursday
1. Calculate the number of cubic inches the figure can hold.2. Calculate the number of square inches needed to cover the figure.3. If all the dimensions are doubled, how is the surface area affected?4. If all the dimensions are doubled, how is the volume affected?
3.5 in
2 in
7 in
1. Calculate the number of cubic inches the figure can hold.
3.5 in
2 in
7 in
5.327 V5.314V
349inV
2. Calculate the number of square inches needed to cover the figure.
3.5 in
2 in
7 in
25.24)5.3(7 inFront 214)2(7 inTop 27)2(5.3 inSide
291)7145.24(2 inTotalS
3. If all the dimensions are doubled, how is the surface area affected?
3.5 in
2 in
7 in298)7(14 inFront 256)4(14 inTop
228)4(7 inSide 2364)285698(2 inTotalS
291inTotalS 2 in
7 in
3.5 in
14 in
4 in
7 in2364inTotalS
491
3642
2
in
in
original
new The new surface area is 4 times larger than the original surface area.
QuizThursday
The first rectangle is dilated to create the second rectangle. What is the area of the dilated rectangle?
6 cm
4 cm18 cm
x cm
What is the area of the new rectangle?
I found the scale factor used by dividing the new side by the original side. I multiplied the other dimension by the scale factor to get the missing dimension. I multiplied the length and width of the new rectangle to get the area.
The first rectangle is dilated to create the second rectangle. What is the area of the dilated rectangle?
The new area is 216 square centimeters.
Enlargement1st: 4 cm by 6 cm2nd: x cm by 18 cm
36
18
Original
New
cm12)3(4
2216
)18(12
cmA
A
Bell RingerFriday
The original figure below is dilated 400%.
1. What type of dilation occurred?2. Calculate the scale factor.3. Calculate the original area.4. Calculate the new area.5. How is the area affected?
2 in
The original figure is dilated 400%.
1. What type of dilation occurred?
2. Calculate the scale factor.
Enlargement
4%400
2 in
The original figure is dilated 400%.
3. Calculate the original area.
4. Calculate the new area.
222 56.12)4(14.3)2(14.3 inr
inNewRadius 842:
2 in
222 96.200)64(14.3)8(14.3 inr
8 in
The original figure is dilated 400%.
5. How is the area affected?
161
16
56.12
96.200
Original
NewSay NO to Oreos!
The new area is 16 times larger than the original area.
2 in 8 in
QuizFriday
Two figures are similar. The scale factor is ½. If the volume of the larger figure is 48 in3, what is the volume of the smaller figure?
What is the volume of the smaller figure?
I cubed the scale factor since volume involves 3 dimensions. I set up a proportion with the volume scale factor. I used the volume of the larger figure and the volume scale factor to find the volume of the smaller figure.
Two figures are similar. The scale factor is ½. If the volume of the larger figure is 48 in3, what is the volume of the smaller figure?
The volume of the smaller figure is 6 cubic inches.
ReductionScale factor: ½Volume of large: 48 cubic in
8
1
2
1
2
13
3
488
1 V
original
new
48
6
68
61
original
new