## Tuesday, February 7, 2012

### The Blackboard In Your Mind - Part 3

We can all safely admit (even to ourselves, if we are not in a confessional or a crowded subway car) that doing arithmetic computations with eyes closed, from memory and using sheer brain power is a challenge, but one that is a worthwhile undertaking. Here are the answers, as well as some observations, regarding the last posting. That makes this post, which are reading, a post-post posting. Or worse, it could be considered a commentary on a past posting. Alliteration and irony combined tend to produce an excess of spittle...an effect which I enjoy witnessing in others but which I try to avoid inadvertantly engaging in myself.
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The following embedded image (although the subject appears wide awake), exemplifies irony:

It's now back to the exercise with some answers in RED.

Here's a new set of operations to work on in the same manner as you did on the previous set, except that now we will use multiplication and division. Never mind about your third-grade teacher's order of operations lecture....simply do the operations in the order indicated, ONE AFTER THE NEXT. I'll give you an answer to check your work within a day or two.

5 x 6 / 2 + 7 x 3 -5 = 61

1) Might these problems be easier/ more difficult if presented in a multi-row format, with a small number of operations per row? Why? A: Multiple rows are generally easier because they are easier to memorize and visualize and because they are seen as smaller, less 'intimidating' problems.

2) Might these problems be easier/ more difficult if presented in a vertical column instead of in a horizontal row? Why? A: It is generally easier to memorize things (words, numbers, shapes, and the like) in columns than in rows, based upon an orientation to data presentation taught to us [habituation] while in school.

Douglas E. Castle for Braintenance