Day 6 - Chapter 1, Digits & Decimals Problem Set

Problem Solving — algebra and arithmetic (GMAT Focus Edition)
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Hi there! Can anyone explain how this problem is solved, to me? : "Simplify .00000256 to the square root of 8."
According to the explanation, I need to write the expression as a decimal raise to a fractional power, using powers of ten to separate the base from the exponent: .00000258(^1/8) = [(256)^1/8] * [(10^-8)^1/8]. But, how do I easily get "2" from (256^1/8)?

Thanks!

Amy
Source: — Quantitative Reasoning |

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by Jim@StratusPrep » Sat Oct 27, 2012 9:31 am
you have to recognize powers of 2:

2, 4, 8, 16, 32, 64, 128, 256, 512, 1024

You don't have to memorize what power they are, just recognize that they are powers of 2...
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