Question

show the calculator answer, significant digits answer and identify the number of significant digits. show all work.
17.0 + 14 - 8.9

make it more clear.

Answer 1

To evaluate the expression \(17.0 + 14 - 8.9\) and identify the significant digits, we'll go through the calculation step by step.

### Step 1: Identify Significant Digits

1. **17.0** has **three significant digits** (the zero after the decimal counts).
2. **14** has **two significant digits** (14 is an integer).
3. **8.9** has **two significant digits** (the nine after the decimal counts).

### Step 2: Perform the Calculation

First, we perform the addition and subtraction:

1. **Addition:**
\[
17.0 + 14 = 31.0
\]

Here, since **17.0** (3 significant digits, decimal) and **14** (2 significant digits, no decimal) are involved, the result should be rounded to the least precise measurement's decimal place, which is the tenths place (from **17.0**).

2. **Subtraction:**
\[
31.0 - 8.9 = 22.1
\]

In the subtraction step, **31.0** has a decimal place (1 decimal) whereas **8.9** has 1 decimal place as well. Therefore, we keep one decimal in our final answer.

### Final Result

The final result is:
\[
22.1
\]

### Step 3: Identify Significant Digits in the Final Result

The result \(22.1\) has **three significant digits**:
- The digits 2 and 2 are significant.
- The digit 1 is significant because it is a non-zero digit.

### Summary

- **Calculator Answer:** \(22.1\)
- **Significant Digits Answer:** \(22.1\) (3 significant digits)
- **Number of Significant Digits:** 3 (in \(22.1\))

Thus, the final result shown with calculations and significant digits is clear:
\[
\text{Final Answer: } 22.1 \quad (\text{3 significant digits})
\]