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Mama Deb
mamadeb
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Mama Deb [userpic]
Algebra!

Yes, *Algebra*.

One of the customers wanted to know how much she should ask for her house such that, after the agent's fee, she still had $700,000. Agent's fee is 5%.

After the agent struggled with the dreaded *math* for a while, she asked me.

I took out a pen and paper, and came up with this formula.

x-0.05x=700,000

0.95x=700,000

I told the agent, who had a calculator, to do 700,000/0.95 and viola! Approximately 737,000, which rounds nicely to $740,000. Easy. And, yeah, fun.

Because, see, algebra is used in real life and all the time. Why won't people believe that? If there wasn't that block, life would be a lot smoother.

And on another note - the online client seems to know what the date is now.

Comments

It isn't the algebra that confounds me. It's the percentages! :)

I desperately needed that formula about a month ago. I'll need it again in five days or so, thanks! :)

*nod* I recently gave a coworker a lesson in percentages.

See, the base formula is fraction/total = percent/100.

So if you're trying to figure out 15% of $65, you do x/65 = 15/100 and go from there to 100x = 15 * 65 and then solve for x.

Or if you're trying to figure out what percentage 8 is of 45, then 8/45 = x/100, 8x = 4500, solve for x. Et cetera.

That saved my life in school and has done so many other times since.

Well, a short and easy way to get 15% of $65 is that 10% is $6.50 and 5% is half of that or $3.25. So 15% is $9.75.

but that only works for nice easy numbers like that. It gets harder with bigger numbers and stranger percentages.

It's quicker for me to do it in my head, since I can eyeball 10% of anything. 10% of 700K is 70K. Split in half to arrive at a 5% figure and it's $35K. Hence 735K.

Algebra = no. Learning to easily figure 10/15/20% so I can leave tips = yes. Everything is relative. *g*

I love algebra, at least at some times. I was the shining star in my old workplace when I was still in Alaska, because I could adjust recipies to work with the materials on hand (in sizes other than doubling or halving).

This made it so that I was able to make my father the out-of-season seasonal muffins that he liked so much for his birthday.

I could adjust measurements as measurements - if this recipe calls for one cup of x and I want to make one third of the recipe, I'd need one third cup of x. If I used recipes at all, I mean.

But (forgive me, I don't bake much), isn't it true that some ingredients don't scale up? That is, if you double the flour, you might not need to double the baking soda?

Some ingredients probably don't, but I don't bake much either in the microcosm. My work experience was macro-baking -- imagine a mixing bowl the size of a very small hot tub, and a mixer that could have passed for a drill press -- and the mix came pre-mixed, just add water, eggs, oil, and flavorings.

Thanks for the idea for a nice word problem :-)

(for the percent chapter in an algebra book)