Monday, October 19, 2009

Estimating Decimals with Multipilication



1.69 x 5 ( tax included )
Younger sibling says it only costs 5 dollars.
Older sibling says it only costs $10.
What are they thinking , how are they estimating ?
The younger sibling is under estimating. $1 x 5= $5.00 front end estimating
The older sibling is over estimating.$2 x $5= $10 rounded it . Relative size .

Is $9.00 enough, and prove it .
$1 x 5= $5.00 $9 - $5= $4.00 left .
0.69 = 0.70 x 5 = 3.5
$5 + $3.50 = $8.50
OR
$1.69 = $2.00 $2.00 x $5 = $10 0.31 = 0.30
0.30 x 5 = 1.50 $10.00 - $1.50 = $8.50


Where does the decimal go ?

2.2 x 1.8= 3960
2.2 rounded = 2
1.8 rounded = 2 x 2 = 4
4 is the near 3.960.

3.9 x 5.8= 22620
3.9 is rounded to 4
5.8 is rounded to 6 x 4 = 24
24 is close to 22.620

2.57 x 0.45= 1.18220
2.57 is rounded to 3
0.45 is rounded to 0.50 x 3 = 1.5
1.5 is the nearest to 1.18220

A pronghorn is 58 kg .
A Dall's weighs 1.5 times as much
How much does Dall's weigh ?
58 kg = 60 kg x 2= 120 kg
60 kg x 1= 60 kg
90 kg is between 120 and 60.

HOMEWORK
46 x 2.5
64 x 4.5
estimate then calculate






29 comments:

  1. Nice going Allison. It was very neat, great video too.

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  2. Good Job Allison. I really like the video, but next time try finding a web site.

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  3. Good Job Allison.
    It was very neat and organized. You explained everything and was very clear of what we had done today. Also the video was well fit in.

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  4. Good job Allison, I love the video, it is so understandable, and also your work is very neat!

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  5. Great Job Allison, your work is neat. For the font size you should make it bigger so its easier to read. I liked the video cause it fits on your Topic.

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  6. Well done Allison, you explained everything we did in class. I like the picture that you used. But instead of putting a video about multiplying decimals, you should have put a video about estimating decimals.

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  7. Great job Allison! Keep up the great work! But next time try to find a website. But great start.

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  8. Nice job Allison, the video is really neat.

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  9. Good job allison you explained evrything clearly. but i think you should of got a web site. but good job all an all

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  10. Good job Allison. Good video and picture. Like the others said try to find a website for more information. Good job Allison!

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  11. Nicely done Allison! The explainations were understandable and the video was nice too. I suggest you use a larger font next time and add a link if you can.

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  12. The informaion was clear and the video was pretty good except the girl was kind of boring. Oh good picture as well.
    P.S. Thanks for posting the homework.

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  13. Nice job Allison. I liked when you made the words "front end estimating" and "rounded it. relative size ." faded and grey.

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  14. I think that you could have made the words that are likely to be the key words, coloured or linked to its definition.

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  15. I also liked when you made the words "Where does the decimal go ?" and "Homework" in colour to show that those were a new section.

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  16. I agree with Hanna. I think that you could have used a larger font. But overall it was well done.

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  17. Great job Allison! I think that it was good but yah like some of the other people sad you should try and find a website. Other then that it was good and very detailed awesome job.

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  18. Great Job Allison!You did pretty good!Keep up the good work!

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  19. Good Job Allison, i really liked watching the video, the picture is really neat and clear to see.

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  20. fantastic job allison i like were you explained everything we did to day and the video was good and good job allison

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  21. good job allison (:. the video was really easy to understand. but i think the font should just be a litter more bigger. but overall good job.

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  22. Nice job Allison, you made everything understandable and clear, I think you forgot to put a website. anyways, good job ! :)

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  23. Good job Allison,you made all the things very easy for me to understand :D. And the video was also very helpful!Also try finding a website though.

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  24. Great job Allison.The video was helpful
    and try finding a website nextime.

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  25. Good job Allison, the video helped alot.

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  26. nice job allison nice video it help me alot and nice picture great job :D

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  27. nice job Allison, the video heped me make it understand easier.

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  28. Great job Allison! I liked how everything was organized and neat. I liked the video, it was very helpful. I liked how you used different colors. Next time find a link an make your font larger. Good Job!

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