Rational or not?

is 9/56 rational? when converted to a decimal it seems to be never ending and it seems like there's no pattern (at least as far as the calculator shows)

Well, relying on a calculator is leading this person astray.

Obviously the number is rational - it's a fraction (!); it fits the definition of a rational number.

The calculator gives 0.160714286 (to nine decimal digits), but if you use long division and continue it till you get just a few digits more, you get 0.16071428571428..., or 0.160714285.

Comments

Anonymous said…
The calculator built into windows can be more helpful because it shows more digits, but you still have to be careful of the rounding in the last digit. It gives 9/56 =
0.16071428571428571428571428571429
10:30 AM, September 20, 2006
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