A0.25
B0.15
C0.3
D0.05
Answer:
D. 0.05
Read Explanation:
Understanding Decimal Numbers and Comparison
To find the smallest decimal number among a given set, compare the numbers systematically.
Step 1: Compare the Whole Number Part
First, look at the digits to the left of the decimal point (the whole number part).
The number with the smallest whole number part is generally the smallest. For example, 0.05 is smaller than 1.05 because 0 < 1.
Step 2: Compare the Decimal Part (if whole parts are equal)
If the whole number parts are the same (e.g., all are 0), move to the digits to the right of the decimal point.
Compare the digits from left to right, starting with the tenths place.
For instance, comparing 0.5, 0.1, and 0.05:
All have 0 as the whole number part.
In the tenths place: 0.5 has 5, 0.1 has 1, and 0.05 has 0.
Since 0 is the smallest digit in the tenths place, 0.05 is the smallest among these three.
Step 3: Compare Further Decimal Places (if initial decimal parts are equal)
If the digits in the tenths place are also the same, move to the hundredths place, then the thousandths place, and so on.
Always compare digits at the same decimal position.
Example: Comparing 0.05 and 0.005. Both have 0 in the whole part and 0 in the tenths part.
In the hundredths place: 0.05 has 5, and 0.005 has 0.
Since 0 < 5, 0.005 is smaller than 0.05.
Important Tip: Equalize Decimal Places
When comparing, it's often helpful to add trailing zeros to the decimal numbers so that all have the same number of decimal places. This makes visual comparison easier.
Example: To compare 0.5, 0.1, and 0.05, convert them to three decimal places: 0.500, 0.100, and 0.050. Now, comparing 500, 100, and 50 (ignoring the decimal point for a moment) clearly shows 50 (from 0.050) as the smallest.