Teaching Math

Last week I purchased a burger at a fast food restaurant for $1.58. The counter girl
took my $ 2 and I was digging for my change when I pulled 8 cents from my
pocket and gave it to her. She stood there, holding the nickel and 3
pennies, while looking at the screen on her register.

I sensed her discomfort and tried to tell her to just give me two quarters,
but she hailed the manager for help. While he tried to explain the
transaction to her, she stood there and cried.

Why do I tell you this? Because of the evolution in teaching math since the
1950s:

1. Teaching Math In 1950s

A logger sells a truckload of lumber for $100. His cost of production is 4/5
of the price. What is his profit?

2. Teaching Math In 1960s

A logger sells a truckload of lumber for $100. His cost of production is 4/5
of the price, or $80. What is his profit?

3. Teaching Math In1970s

A logger sells a truckload of lumber for $100. His cost of production is
$80. Did he make a profit?

4. Teaching Math In 1980s

A logger sells a truckload of lumber for $100. His cost of production is $80
and his profit is $20. Your assignment: Underline the number 20.

5. Teaching Math In 1990s

A logger cuts down a beautiful forest because he is selfish and
inconsiderate and cares nothing for the habitat of animals or the
preservation of our woodlands. He does this so he can make a profit of $20.
What do you think of this way of making a living?

Topic for class participation after answering the question: How did the
birds and squirrels feel as the logger cut down their homes? (There are no
wrong answers, and if you feel like crying, it's ok. )

6. Teaching Math In 2009

Un hachero vende una carretada de maderapara $100. El costo de la
producciones es $80. Cuanto
dinero ha hecho?

7. Teaching Math In 2013
Who cares, just steal the lumber from your rich neighbor's property. He
won't have a gun to stop you, and it's OK anyway cuz it's redistributing
the wealth.

Sad it is so true. Math is a beautiful thing but it seems to be so poorly taught now. Go to a store when the power is off and the people behind the till don't even know how to make change so won't let you buy anything.

That reminds me, I have to find out how to get the correct answer to my son's grade seven math question. He was one of a few children chosen to compete at the university. Definitely a big fish in a small pond!
Any one know how?

I cannot for the life of me figure this out and get their answer: (D) 253

8. Last summer Sam worked for a cycle dealer. The dealer agreed to pay him $210 and a new bike
for seven weeks of work. But Sam didn't enjoy the job and quit after four weeks. The dealer
gave him $21 and the bike. How much was the bike worth?
(A) $216 (B) $225 (C) $231 (D) $253 (E) None of these

The hint is no help either:

8. Sam received $21 plus the bike for work of value 4/7($210 + the bike).
I solve this and get $77?
Any other way I end up with $120.75.
Pretty sad I can't do a grade 7 math question! Give me calculus any day -lol

Hmmm, I've tried a couple of different ways and get $231.

Fowler wrote:Hmmm, I've tried a couple of different ways and get $231.

I think I got that once too. Funny how the boy could care less, and I struggle every time I see the question, to try and answer it.... Guess I need to take up the Xbox!

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HigginsRAT wrote:

auntieevil wrote:That reminds me, I have to find out how to get the correct answer to my son's grade seven math question. He was one of a few children chosen to compete at the university. Definitely a big fish in a small pond!
Any one know how?

I cannot for the life of me figure this out and get their answer: (D) 253

8. Last summer Sam worked for a cycle dealer. The dealer agreed to pay him $210 and a new bike
for seven weeks of work. But Sam didn't enjoy the job and quit after four weeks. The dealer
gave him $21 and the bike. How much was the bike worth?
(A) $216 (B) $225 (C) $231 (D) $253 (E) None of these

The hint is no help either:

8. Sam received $21 plus the bike for work of value 4/7($210 + the bike).
I solve this and get $77?
Any other way I end up with $120.75.
Pretty sad I can't do a grade 7 math question! Give me calculus any day -lol

Think I worked it.



$210 + $253 value of bike = $463 if Sam had worked the 7 weeks.

Sam worked only 4 of the 7 weeks, so 4/7 = 0.571428 is the portion he should be paid

$463 x 0.571428 = $264.57 is the money and bike value he was paid


Money part:

$210 / 7 weeks = $30 per week
4 weeks x $30 = $120 in monetary wages owed.
Sam is owed $120 and is only given $21
$120 - $21 = $99 was taken off the monetary amount owed him--part of value of the bike.

$210 x 0.571428 = $120 earned - $21 paid in cash = $99 bike value

Money portion for 4 of 7 weeks is $120.


Bike part:
$21 = 4/7($210 + the bike).

$210 cash + $253 bike value = $463 value if worked seven weeks.
4/7 = 0.571428 portion Sam worked

$253 bike value / 7 weeks = $36.17 per week
$36.17 x 4 weeks = $144.57 portion of bike earned.

Bike portion for 4 of 7 weeks is $144.57.


Four Weeks worked:
($21 paid plus $99 value of bike) $120 cash earned + $144.57 bike portion earned = $264.57 for four weeks of work.


7 weeks ($210 cash + $253 bike) $463 x 4 weeks (4/7) 0.571428 = $264.57 four weeks.


Validation...

3 of 7 weeks not worked...

3 x $30 cash value of per week = $90
3 x $36.17 bike value of per week = $108.51

$90 + $108.51 = $198.51 for three weeks left not worked

$264.57 for 4 weeks + $198.51 for 3 weeks = $463.08 for seven weeks work ($210 + $253) excluding rounding errors for the eight cents.



Tara - my head hurts...no more HOMEwork...tanks--I feel like I got hit by a brick...from the wall...leave me alone now, not a pretty sight

I think you lost me... How do you do the question without knowing the answer first???

Fowler wrote:[You must be registered and logged in to see this image.]

It was a sad year when both The Far Side and Calvin and Hobbes cartoonists, Larson and Waterson retired

I get $231 for the value of the bike, although I'm pretty rusty at math.
4(210/7+b/7)=21+b
(840+4b)/7=21+b
840+4b=147+7b
693=3b
231=b

Reminds me of a high school math question involving a farmer wanting to build a fence beside his barn. I thought it was stupid, so my answer was ...

1.) How big is the barn?
2.) How many feet of fencing are in the roll of wire?
3.) How many and what kind of animals does he want to put inside the fence?

I didn't get any points for that. Clearly, the math teacher was city-raised.

.

rosewood wrote:I get $231 for the value of the bike, although I'm pretty rusty at math.
4(210/7+b/7)=21+b
(840+4b)/7=21+b
840+4b=147+7b
693=3b
231=b

That is how I would have done it Rosewood. Like you, I am rusty but loved Math in school. Word problems were not always my forte, but loved algebra a lot.
Just looking at the question and not figuring it out I would have chosen $231 as well, but that method would get me into trouble sometimes in school!

Thanks for the C&H. Love them and miss them!

Tara is right, I put it in the to hard basket when I first looked at it. Easy to say after, ya, that's waht I would have said.

I respectfully decline to expose my complete incompetence at math by even attempting to solve the problem! I know it's American and I'm not...... but in this case I will plead the Fifth!

I respectfully decline to expose my complete incompetence at math by even attempting to solve the problem! I know it's American and I'm not...... but in this case I will plead the Fifth!

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Wow, you guys are awesome! Much faster at a reply than the teacher -lol
Those poor kids had to do 26 questions in 1 hour. Wrong answers cost them 2 points, and correct gained them 4. That of course helps eliminate guessing.
For me, so often I make stupid adding or subtraction errors, so getting part marks for nearly making it, often saved my hide in school.
We are starting on next years tests. Maybe he'll have a hope of getting through the test.
Be ready for more of these questions in the future -lol
Aspirins all around!

I always despised the 'take marks away for wrong answers' system. Sure it stops guessing but it also discourages trying (especially in something like math).

Yes, discouraging children from trying is a bad thing.
Multiple choice is often a simple recall thing, and hardly tests knowledge IMHO
Much harder to have to recall the answers.
Math is best answered in full, as lots of times people get the right answer, but for the wrong reason. If you can show your work, it really shows you know your stuff. Plus it allows for partial marks for near successes.
Much more time consuming to mark a full answer test though.
Good thing I never became a teacher, the kid's would have hated me...