Maybe an actual original idea for the #MTBoS?

There has been recent discussion on blogs and twitter about how to teach dividing by fractions besides just telling the kids to multiply by the reciprocal - the why part.

It got me to thinking: how many pennies would line up on a ruler? A penny's diameter is 3/4 inch, so I did 12 divided by 3/4 but really multiplied by the reciprocal 12 times 4/3 and I got 16. Sixteen pennies should fit on a ruler.

So, then I thought about it some more:

In just looking at 4 inches of the ruler and putting one penny in each inch, I then thought this:

So, in four inches there would be 5 pennies because four fourths makes one whole.

Next I multiplied by 3 and got 15 - what the heck?! Now, mind you, I woke up thinking all this at 6 am on a Saturday morning. I knew I was wrong but it seemed to work.

It lead me to a joke (again early morning):

What does 1 penny plus 1 quarter equal? An inch :) I like it - that's original too!

So, then I was thinking about 2 pennies. Two pennies would be an inch and half so four pennies would be three inches, but then I have a whole inch left over and a penny is only 3/4 inch so I would have room for 1 penny with 1/4 left over -ahhhhhh - there it is. I would have three 1/4's leftover and that equals my sixteenth penny.

I went wrong in thinking that four fourths makes the whole. Only three fourths makes a whole

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**penny**
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