Question

which list shows the numbers in order from least to greatest?
a 0.729, 0.7, 0.639, 0.6
b 0.6, 0.7, 0.639, 0.729
c 0.639, 0.6, 0.7, 0.729
d 0.6, 0.639, 0.7, 0.729

Explanation:

Step1: Compare tenths place

The tenths digits are: $0.6$ (6), $0.639$ (6), $0.7$ (7), $0.729$ (7). So numbers with 6 in tenths are smaller than those with 7.

Step2: Compare hundredths place for 0.x numbers

For $0.6$ and $0.639$: $0.6 = 0.600$, its hundredths digit is 0; $0.639$ has hundredths digit 3. So $0.6 < 0.639$.

Step3: Compare hundredths place for 0.7 numbers

For $0.7$ and $0.729$: $0.7 = 0.700$, its hundredths digit is 0; $0.729$ has hundredths digit 2. So $0.7 < 0.729$.

Step4: Combine the order

Putting all together: $0.6 < 0.639 < 0.7 < 0.729$.

Answer:

D. 0.6, 0.639, 0.7, 0.729