Friday, April 4, 2008

The Great Coin Jar Experiment

Not sure when we last counted the coins in the family coin jar... but it was time this week. The jar was full, nearly to the top, and was at risk of injuring someone or being tampered with. So I made it into a mini-experiment for Seth.

First of all, everyone in the family guessed. Dad: $285, Mom: $375, Seth: $217, Luke: $240, and Caleb (future contestant on The Price is Right): $242. Hopefully, by using a scientific method, we could made an educated guess and get closer than any of our wild guesses.

The approach was to weigh a sample of coins, count the amount of the sample, calculate the $ per pound, weigh all the coins, and multiply. So we scooped out a cup of coins and weighed it to be roughly 1.75 pounds. Subtracting out the weight of the scoop, we were left with 1.65 pounds. Then Seth counted those coins and it contained $18.97. That worked out to about $11.50 per pound. We dumped those coins back in the big jar.

Next was the weighing of the big jar of coins on the family scale. It was a whopping 30.2 pounds. We dumped the coins into 2 pillow cases, then we weighed and subtracted out the empty jar, leaving a net of 27.7 pounds of coins. That's a lot of coins!

So with 27.7 pounds of coins at $11.50 per pound, we have a mathematical guess of $318.47.

The next day, off to the bank the family went. They have a machine that counted all the coins, which amounted to $307.37! So the winners were:

1. Math: ($11.10 difference)
2. Dad: ($22.37)
3. Caleb: ($65.37)
4. Luke: ($67.37)
5. Mom: ($67.63)
6. Seth: ($90.37)


1 comment:

Blain Dillard said...

Update to this one: Having never seen the jar full of coins, but only seeing the empty jar, and hearing the story... My dad (aka Paw Paw) guessed $300. So, he defeated Math:

1. Paw Paw ($7.37 difference)
2. Math: ($11.10)
3. Dad: ($22.37)
4. Caleb: ($65.37)
5. Luke: ($67.37)
6. Mom: ($67.63)
7. Seth: ($90.37)