I already wrote about dividing fractions here and here.

I use the explanation of “dividing by one” to explain why 5/6 divided by 2/3 is the same as 5/6 times 3/2.

But when I was asked recently about how the “common denominator” strategy worked, my muted response was, “Because it does.” I didn’t mean to be a jerk, rather I just hoped she’d go along with me.

I grabbed a piece of paper and wrote 5 ÷ 3 = 5/3. She was already bored with me. Then I added 1s under the numbers to show 5/1 ÷ 3/1 = 5/3. *Right, right?* I then changed the problem to 10/2 ÷ 6/2 = 10/6… = 5/3. *Still okay, right?*

Before I could give another example, she took the paper and rubbed it on my head. Rude.

***

The real common denominator is we’re all in this together to #flattenthecurve. This tweet is like rainbow.

My elderly neighbor is self-isolating. So the neighbor kids are playing her a cello concert from her patio. pic.twitter.com/g6Nr2HNVho

— Jackie Borchardt (@JMBorchardt) March 16, 2020

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