Khan/khan-exercises — Issue #10283: Percentage word problems 1 - Precision is too high
Author: KhanBugz
Created: 2012-01-04 05:24:34+00:00
State: open
Labels: chrome, hard, scratchpad, win7

Reporter: rjacobson@ymail.com

I'm working through the Percentage Word Problems 1 module. I'm attempting to "be good" and do them without a calculator.

Most of these problems require long division of irrational fractions rounded to the hundreths place. To complete these problems, they therefore requires some *very long* division -- calculation to the thousandths place to determine the correct direction of rounding.

I've spent over an hour working through these, and writing as small as possible on the scratchpad just to get the long division to fit. This also increases the possibility of an arithmetic error -- if I were to make an error close to the end of this module, and have my progress set back substantially, I think'd throw my computer against the wall. :-)

All of this combines to make this module more about really long division, and less about proving the student's actually comprehension of percentage problems. Could you perhaps re-do these problems so that they either don't use irrational fractions, or at least reduce the amount of accuracy required for the percentage answers? Thanks.

[percentage_word_problems_1.html?seed=148&problem=backward-percentages](http://sandcastle.khanacademy.org/media/castles/Khan:master/exercises/percentage_word_problems_1.html?seed=148&problem=backward-percentages&debug)

[Answer timeline](http://sandcastle.khanacademy.org/media/castles/Khan:master/exercises/percentage_word_problems_1.html?seed=148&problem=backward-percentages&debug&activity=%5B%5D)

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