sigh - I can't do grade 5 math!

[flowrider]

Man I've never heard those terms and I've taught grades 4,5,6, and 7. Currently 7. I've never taught it that way. I like to teach things as simply as possible.

[damian]

Where are they teaching this in Grade 5? I remember learing that stuff back in Grade 8...

[Xayvian]

Originally posted by stillgoing
ok, here's some sample questions:

Use front end estimation to find the estimate to the nearest thousand:
2691+385
5968+7154
8148+2731

Now, use oneup, one down to thousands to find the estimate, using the same numbers.

Then, use backend rounding to the nearest hundred to find the estimate:
207+416
626+819
661+592


Good luck. Without really knowing the strategy, who can say what the correct answers are?

I have never heard these terms before but here are my guesses.

For front-end estimation I think you use the two most significant digits so you get:

2691+385 2600+300=2900
5968+7154 5900+7100=13000
8148+2731 8100+2700=10800

For one up, one down to thousands,

2691+385 3000+0=3000
5968+7154 6000+7000=13000
8148+2731 9000+2000=11000

For back-end rounding to nearest hundred,

207+416 200+400=600
626+819 600+800=1400
661+592 700+600=1300

[sanrensho]

More than you ever wanted to know about front-end estimation here.

Straight from the horse's mouth, as it were. I'm glad I don't have to deal with this stuff for another 5 years.

[BiG D]

Hahahaha a board of high school students/ graduated adults working out Grade 5 math problems as a team!
go nsmb

The kids may say the teacher did not explain it to them... but I mean of course the teacher didnt... catch my drift

[stillgoing]

Flowrider: Ha! I was hoping you'd show up here - I seemed to remember you stating somewhere along the way that you were an elementary school teacher. If you go out your front door, head east 2 blocks - that's where they teach this stuff.

Sanrensho - Thanks for the link. Looks like even the teaching commuity can't agree on just what Front End Estimating is. I think I undersatnd back end rounding, just by the name and the question. 1up, 1 down is probably exactly as Xayvian says, which in my opinion is just plain silly.

Xayvian - thanks also.

Big D: Yeah, it all seems a little silly - us discussing grade 5 math. And, I'm sure the teacher mouthed the words to explain it all, but obviously it did't sink in. Now - My son- OK, For him to miss a point, I'm not surprised. But my Daughter sucks knowledge for breakfast and proves it in her marks (she cried when she missed getting straight A's last year, the solitary B in fine arts pissed her off.) So, I think here the concept was not put across very well ( if at all)

[switch]

Teachers don't teach any more. They give assignments, send the kids home expecting the parents to do the teaching, and then complain how hard it is to be a teacher.

[Craz]

Front end estimation is where you estimated using only the FIRST digit of a number... eg: 2486 is 2000. 368 is 300 so 2486+368=2300