standard_description: Know that numbers that are not rational are called irrational. Understand informally that every number has a decimal expansion; for rational numbers show that the decimal expansion repeats eventually, and convert a decimal expansion which repeats eventually into a rational number.
problem_activity: Task
Malia found a "short cut" to find the decimal representation of the fraction $\frac{117}{250}$.  Rather than use long division she noticed that because $250 \times 4 = 1000$,
$$\frac{117}{250} = \frac{117 \times 4}{250 \times 4} = \frac{468}{1000} = 0.468.$$
For which of the following fractions does Malia's strategy work to find the decimal representation?
$$\frac{1}{3}, \frac{3}{4}, -\frac{6}{25}, \frac{18}{7}, \frac{13}{8} \;\; {\rm and} \;\; -\frac{113}{40}.$$
For each one for which the strategy does work, use it to find the decimal representation.
For which denominators can Malia's strategy work?


aligns: no