Random musings

[MrCrowesGarden]

This picture (spoiler for size):

[SHOW]

has been a point of argument between me and some friends on Facebook.

I'm assuming (hoping) the instructions at the top of this assignment said something to the effect of "estimate by tens."

At the same time,

1) Why, if you're encouraging a student to learn how to estimate by tens, would you use a number that doesn't have a 0 in the ones place
2) Why would you use the exact answer in the example unless you're trying to be sadistic?

[Arthur Dent]

This picture (spoiler for size):

[SHOW]

has been a point of argument between me and some friends on Facebook.

I'm assuming (hoping) the instructions at the top of this assignment said something to the effect of "estimate by tens."

At the same time,

1) Why, if you're encouraging a student to learn how to estimate by tens, would you use a number that doesn't have a 0 in the ones place
2) Why would you use the exact answer in the example unless you're trying to be sadistic?

1) Because, then it wouldn't be estimating. Presumably, the point is to show that you can get an approximate answer quickly by rounding to numbers that are easier to work with.
2) I agree that this is a poor choice.

[MrCrowesGarden]

This picture (spoiler for size):

[SHOW]

has been a point of argument between me and some friends on Facebook.

I'm assuming (hoping) the instructions at the top of this assignment said something to the effect of "estimate by tens."

At the same time,

1) Why, if you're encouraging a student to learn how to estimate by tens, would you use a number that doesn't have a 0 in the ones place
2) Why would you use the exact answer in the example unless you're trying to be sadistic?

1) Because, then it wouldn't be estimating. Presumably, the point is to show that you can get an approximate answer quickly by rounding to numbers that are easier to work with.
2) I agree that this is a poor choice.

To your point on #1, I was assuming they would ask if 70 or 80 (or another number ending in zero) would be a reasonable estimate.

[Arthur Dent]

Yeah. It's weird that the teacher correction says "Estimate 100-30=70" when you are supposed to decide if 75 is a good estimate. You could just as well do 100-25, which almost as easy.

[Molly]

a turkey and miracle whip sando after thanksgiving wooooooooooo

[lukethedrifter]

Incredibly poorly constructed math question. When it's easier to get the actual answer than the estimated one you're doing it wrong.

[go birds]

Back when i learned basic math, the rule was, when rounding numbers anything 5 and above gets rounded up.

im guessing that's whats going on here?

[Jocephus]

[wart57]

Incredibly poorly constructed math question. When it's easier to get the actual answer than the estimated one you're doing it wrong.

This kind of things maddens us old farts. Us old farts were taught math was concrete and had only one true answer, not reasonable answers. But I can understand why it is being done, if exact numbers aren't important and they are learning to estimate. But it just throw us old farts off.

[lukethedrifter]

Incredibly poorly constructed math question. When it's easier to get the actual answer than the estimated one you're doing it wrong.

This kind of things maddens us old farts. Us old farts were taught math was concrete and had only one true answer, not reasonable answers. But I can understand why it is being done, if exact numbers aren't important and they are learning to estimate. But it just throw us old farts off.

That's not what they are doing.
You have kids. They do a math problem and come up with an answer that is way off. You say, "Does that answer even make sense?"
They are teaching kids to understand if what they have come up with is a reasonable answer. By estimating. But some times the people coming up with the questions don't get it either so they only confuse people more.