[Math4u] Prioritities of Operations

Hi, Guys,

If I were teaching this to an elementary student, I would tell them to perform the operations from left to right, if they have the same priorities (e.g., addition and subtraction, and multiplication and division).

However, if I were to teach this to a student who already has taken negative numbers, I will tell them to apply the definition of subtraction/division. For example:

53 + 31 - 24 - 8 + 6 = 53 + 31 + (-24) + (-8) + 6.

Then add the positive numbers together and the negative numbers together.

So, going back to our example:

[53 + 31 + 6] + [(-24) + (-8)] = 90 + (-32) = 58.

See, we did addition several times and subtraction only once.

As for multiplication/division, that may be done also:

12 ÷ 3 x 5 ÷ 10 = 12 x (1/3) x 5 x (1/10) = (12 x 5)/(3 x 10) --> (This is much better written on paper. Ü)

And since the only operations are multiplication and division, we can do cancellations, or perform separately the multiplications for the numerator and the denominator, then perform the division.

Now, wouldn't that be neater than memorizing which goes first? (At least, it wasn't Who's at first.)

Thanks.

Balty

"If you can't do your job in an eight-hour work day, then either you have too much work assigned or you're incompetent." - Michael LeBoeuf, Ph.D.
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