Because you don't always have a calculator? Sorry, is this legit? Or some kind of joke?
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Kay
3/17/2014 02:07:56 pm
...when have you had to multiply numbers with 3 or more digits? Let alone when you've had to do it and not had a cell phone in your pocket?
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Chris Brownell
3/21/2014 04:38:22 am
I don't buy the "you don't always have a calculator" reason much anymore.
That said, I can see some use in demonstrating and minimally experiencing multi-digit multiplication. I do not believe that it ought to be raised to the level of Focus Standard at any grade level though.
The usefulness I can see is two-fold at least: 1. it reinforces the structure of the number system, and 2. this structural awareness can be utilized in later understandings in the Algebra curriculum where we generalize arithmetic from polynomials base ten to polynomials of any base (this is precisely what happens when you take 2*10^2 + 4*10^1 +8*10^0 and make it 2x^2 + 4x +8).
Both of these aim at structural understanding of the mathematics of numbers, which is a large cognitive goal of all mathematical education.
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James Helak
10/8/2014 05:17:14 am
Really?
This sounds like a query posed by a student.
Following that logic, in the age of google and siri, why teach them anything at all other than rudimentary typing, speaking, and reading skills? They can always just google the answer.