#MakeItReal Moment Number 12

Measuring Priceless

So…this just happened.

I love incredible events like this, so when I saw a former math professor of mine post about it on facebook and noticed the first comment, I had to take action.

Instant Relevance is the idea of using what’s happening now, and what matters to you and your students, to engage in excellent opportunities to learn. I couldn’t pass this one up. So I took the straightforward route and went to my calculator and treated this like a simple interest investment. The formula for simple interest is I = PxRxT, or the Interest (earned amount) is equal to the Principal (starting amount) multiplied by the interest rate and the time. We know three out of those four things. What we have is this:

$450,312,500 = $59 x R x 58 years.

To start solving for the interest rate, divide the interest by both the $59 and the 58 years and you end up with 131,593.37, which is a ridiculously large number for a percent, and isn’t even really all that helpful yet. You see, in most of these problems, our answer comes out to be something like 0.05, which means the rate is 5%. So the ACTUAL interest rate needed to return this kind of investment is 100 times greater than what we got. In other words, 13,159,337% interest.

BUT WAIT!!!! THERE’S MORE!!!!

I didn’t ask my math professor where he got the $59 from, so I checked. The painting sold for 45 Pounds in 1958, which, it turns out, converts to $59 in today’s money, but with inflation, is $125 in 1958 money. So, time to start over!!!

$450,312,500 = $125 x R x 58 years

For a mere adjustment to the low, low interest rate of just 6,211,207%. 

Follow Up Questions:

Is Mark, the facebook commenter, right? How could it be so different and seemingly so much more reasonable than what I got?

How long would it take if we knew we had an absolute cap of 10% compounded annually?

How could you use this event in Art, Science, ELA, Social Studies and other classes?

So my question to you is this: How will you use this extraordinary circumstance and likely once in a lifetime opportunity to quantify “Priceless” in your classroom, before it’s no longer relevant? 

Share your ideas and lessons with me at the #MakeItReal Hashtag on twitter!!!

Remember to use the #MakeItReal Hashtag for sharing ideas!

Connect with Denis Sheeran at Denissheeran.com

Twitter: @MathDenisNJ and

#MakeItReal Chat Every Wednesday 9:30 pm EST for 30 Minutes.

Read Instant Relevance

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