Question

how many sig figs are there in each number 2.5010 2.501 0.025 0.002 0.0250

Explanation:

For 2.5010:

Step1: Recall sig fig rules

Significant figures (sig figs) rules: Non - zero digits are significant. Zeros between non - zero digits are significant. Trailing zeros in a decimal number are significant.
For 2.5010, the digits are 2, 5, 0, 1, 0. The non - zero digits 2, 5, 1 are significant. The zero between 5 and 1 is significant, and the trailing zero after 1 is also significant.
So we count them: 2, 5, 0, 1, 0. That's 5 significant figures.

For 2.501:

Step1: Apply sig fig rules

Non - zero digits 2, 5, 1 are significant. The zero between 5 and 1 is significant.
Count the digits: 2, 5, 0, 1. So there are 4 significant figures.

For 0.025:

Step1: Apply sig fig rules

Leading zeros (the zeros before 2) are not significant. The non - zero digits 2 and 5 are significant, and the zero between the leading zeros and 2 is not significant, but the zero between 2 and 5? Wait, no, 0.025 is 2.5×10⁻². The non - zero digits 2 and 5 are significant, and the zero between them? Wait, 0.025: the first non - zero digit is 2, then 5. The zeros before 2 are leading zeros (not significant). So we count 2 and 5, and the zero? Wait, no, 0.025 is two significant figures? Wait, no: 0.025. The 2 and 5 are significant. The zeros before 2 are placeholders. So number of sig figs is 2? Wait, no, wait: 0.025. Let's write it in scientific notation: 2.5×10⁻². So the significant figures are 2 and 5, so 2 significant figures? Wait, no, wait, 0.025: the digits are 0, 0, 2, 5. Leading zeros are not significant. So 2 and 5 are significant. So 2 significant figures? Wait, no, wait, maybe I made a mistake. Wait, 0.025: the 2 is the first non - zero digit, then 5. So the number of significant figures is 2? Wait, no, let's check the rules again. Leading zeros (zeros to the left of the first non - zero digit) are not significant. Zeros between non - zero digits are significant. Trailing zeros in a decimal are significant. So for 0.025, first non - zero digit is 2, then 5. So 2 and 5 are significant. So 2 significant figures? Wait, no, wait, 0.025: is the zero between 2 and 5? No, 0.025 is 0.025, so after the decimal, we have 0, 0, 2, 5. So the first non - zero is 2, then 5. So two significant figures.

Wait, no, wait, maybe I messed up. Let's take another approach. The rule for significant figures:

1. All non - zero digits are significant.
2. Zeros between non - zero digits are significant.
3. Zeros at the end of a number and to the right of the decimal are significant.
4. Zeros at the beginning of a number (leading zeros) are not significant.

So for 0.025:

• Leading zeros (the two zeros before 2) are not significant.
• The 2 and 5 are non - zero digits, so they are significant. So number of sig figs is 2.

For 0.002:

Answer:

s:

• 2.5010: $\boldsymbol{5}$
• 2.501: $\boldsymbol{4}$
• 0.025: $\boldsymbol{2}$
• 0.002: $\boldsymbol{1}$
• 0.0250: $\boldsymbol{3}$