Sure, let's solve these problems by following the rules of significant digits:
### 1. [tex]\( 17.800 \text{ mL} - 4.97 \text{ mL} \)[/tex]
First, we perform the subtraction:
[tex]\[ 17.800 - 4.97 = 12.83 \][/tex]
When performing subtraction, the result should be rounded to the least number of decimal places in the numbers being subtracted. Here, 4.97 has two decimal places, which is the least number of decimal places among the numbers.
Therefore, the answer should be:
[tex]\[ 12.83 \text{ mL} \][/tex]
### 2. [tex]\( 6.5 \text{ mL} + 9.620 \text{ mL} \)[/tex]
Next, let's add these numbers:
[tex]\[ 6.5 + 9.620 = 16.120 \][/tex]
When performing addition, the result should again be rounded to the least number of decimal places in the numbers being added. Here, 6.5 has one decimal place, which is the least number of decimal places.
So, rounding 16.120 to one decimal place:
[tex]\[ 16.1 \text{ mL} \][/tex]
### 3. [tex]\( 0.577 \text{ mL} + 8.80 \text{ mL} \)[/tex]
Lastly, we add these two measurements:
[tex]\[ 0.577 + 8.80 = 9.377 \][/tex]
For this addition, the result should be rounded to the least number of decimal places in the numbers being added, which is two decimal places (from 8.80).
Hence, rounding 9.377 to two decimal places:
[tex]\[ 9.38 \text{ mL} \][/tex]
These are our final answers:
1. [tex]\( 17.800 \text{ mL} - 4.97 \text{ mL} = 12.83 \text{ mL} \)[/tex]
2. [tex]\( 6.5 \text{ mL} + 9.620 \text{ mL} = 16.1 \text{ mL} \)[/tex]
3. [tex]\( 0.577 \text{ mL} + 8.80 \text{ mL} = 9.38 \text{ mL} \)[/tex]
