Wednesday, November 3, 2010

Math Homework Book Pg 20-21

1. Estimate 6.6 ÷ 2.3
6 ÷ 2 = 3 Front End Estimation



2.


Estimate 6.6 ÷ 2.3

6 ÷ 2= 3 underestimate
8 ÷ 2= 4 overestimate
-Numberline estimation



3. [C] 25.73 [÷] 3.1 [=] 8.3
-Estimate then use a calculator


4. Divide 20.4 ÷ 3
- Divide as whole numbers then estimate as decimal.

5. Without calulating the answer, place the decimal point in the correct position. Show the estimate that helped you place the deciaml point.

a) 82.4 ÷ 20 = 4.12

-80 ÷ 20 = 4

b) 3.12 ÷ 0.6 = 5.2

3 ÷ 0.5 = 6

c) 2.132 ÷ 0.4 = 5 .33

3 ÷ 0.5 = 6

d) 27 ÷ 0.45 + 60.00

30 ÷ 0.50 = 60

e) 4.026 ÷ 0.6 = 6.71

4 ÷ 0.5 = 8

f) 33.12 ÷ 6.9 = 4.8

30 ÷ 5 = 6

6. Estimate each answer and show your thinking. Then, use a calculator to determine each asnwer.

a) 5.24 ÷ 0.5 = 10.48

Estimate: 5 ÷ 0.5 = 10

b) 68.22 ÷ 0.6 = 113.7

Estimate: 50 ÷ 0.5 = 100

c) 2.142 ÷ 0.07 = 30.6

Estimate: 2 ÷ 0.07 = 28

d) 111.6 ÷ 4 = 27.9

Estimate: 100 ÷ 4 = 25

7. What is the cost of each purchase before tax? Show your calculations.

a) 3 oatmeal barsfor $7.50

$7.50 ÷ 3 = $2.50

b) 5 cans of tuna for $5.30

$ 5.30 ÷ 5= $1.06

c) 6 lemons for $2.99

$3.00 ÷ 6 = $ 0.50

8. George has $10.50 to spend on energy bars. HOw amny can he buy if they cost $0.70 each, including tax?

$10.50 ÷ $0.70 = $15.00

George can buy 15 enrgy bars.

9. Carmen earns $8.30 per hour. She wants to buy a jacket that cost $124.50. How many hours will she have to work to have enoguh money to buy the jacket? Estimate, then use a claculator to determine the asnwer.

125 ÷ 10 = 12.5 - estimated

124.50 ÷ 8.30 = 15- calculated

10. withought calculating the asnwer, circle the larger value . Explain your thinking.

a) 7.8 ÷ 0.98 or 7.8 ÷ 1. 1 is larger than 0.98

b) 16 ÷ 0.5 or 25. 16 ÷ 0.5 = 32

c) 1500 or 2 ÷ 0.001. 2 ÷ 0.001 = 2000

d) 9.3 ÷ 1.02 or 9.3. 9.3 ÷ 1.02 = 91

e) 536 ÷ 0.72 or 536 ÷ 0.68. 0.72 is larger than 0.68

15 comments:

Anonymous said...

good job i can tell you worked really hard on this..Next time try to find a video from youtube

Ace8-17 said...

Great job Caleb! You did a really good job on explaining each answer.

jaydin873 said...
This comment has been removed by the author.
Riley 906 said...

good job next time maybe you could add a picture I like how at the end you made it colorful

jaydin873 said...

good job but maybe you could you could of added a video but I like it

Taylor 7-72 said...

good job ! it really helped me !

samantha8-14 said...

good job caleb! but i think it will help if there was a video

melina814 said...

good job caleb !! maybe next time you should add a video.

alyshiad814 said...

good job! i like the way you did it and explained it, very good job!!!

GurpreetS9-05 said...

good job Caleb but try to add a viedo but good job

raeesa814 said...

good job! i liked how you explained it ... but next time try to add a vidio ..and maybe apicture.

michael8-17 said...

Good job Caleb you explained everything very easy to understand. You could of added a link. But anyways you did a great job.

angela816 said...

Good job Caleb!Although it could have helped people more if you added a video.

Alexia873 said...

good job Caleb. I liked how you explained it.

Ashley772 said...

Good job! I liked how you explained the answers. But next time you should add a video and a link and maybe a picture so I can understand it a little better!