Let's work through the problems step by step.
a. Adding Two Scientific Numbers
We'll choose \(3.2 \times 10^4\) and \(1.95 \times 10^6\).
Step 1: Make the exponents the same.
To add these two numbers, we can express both numbers with the same exponent. The larger exponent will be used, which is \(10^6\).
Convert \(3.2 \times 10^4\) to \(10^6\):
\[ 3.2 \times 10^4 = 3.2 \times 10^4 \times \frac{10^2}{10^2} = 3.2 \times 10^6 \times 10^{-2} = 0.032 \times 10^6 \]
Now our numbers are:
- \(0.032 \times 10^6\)
- \(1.95 \times 10^6\)
Step 2: Add the numbers.
\[ 0.032 \times 10^6 + 1.95 \times 10^6 = (0.032 + 1.95) \times 10^6 = 1.982 \times 10^6 \]
Final result of addition:
\[ 3.2 \times 10^4 + 1.95 \times 10^6 = 1.982 \times 10^6 \]
b. Subtracting Two Scientific Numbers
We'll choose \(4.82 \times 10^{12}\) and \(2.56 \times 10^{-2}\).
Step 1: Make the exponents the same.
In this case, the difference between \(10^{12}\) and \(10^{-2}\) is quite large, so we should express both with the larger exponent, \(10^{12}\).
Convert \(2.56 \times 10^{-2}\) to \(10^{12}\):
\[ 2.56 \times 10^{-2} = 2.56 \times 10^{-2} \times \frac{10^{14}}{10^{14}} = 2.56 \times 10^{12} \times 10^{-14} = 0.0000000000256 \times 10^{12} \]
Now our numbers are:
- \(4.82 \times 10^{12}\)
- \(0.0000000000256 \times 10^{12}\)
Step 2: Subtract the numbers.
\[ 4.82 \times 10^{12} - 0.0000000000256 \times 10^{12} = (4.82 - 0.0000000000256) \times 10^{12} \]
Since \(0.0000000000256\) is very small compared to \(4.82\), we can approximate:
\[ 4.82 - 0.0000000000256 \approx 4.82 \]
So,
\[ 4.82 \times 10^{12} - 2.56 \times 10^{-2} \approx 4.82 \times 10^{12} \]
Final result of subtraction:
\[ 4.82 \times 10^{12} - 2.56 \times 10^{-2} \approx 4.82 \times 10^{12} \]
In summary:
- For addition: \(3.2 \times 10^4 + 1.95 \times 10^6 = 1.982 \times 10^6\)
- For subtraction: \(4.82 \times 10^{12} - 2.56 \times 10^{-2} \approx 4.82 \times 10^{12}\)