Express the following numbers into standard form: a) 3293.02 b) 0.00342 c) 0.284 d) 397203

It was moved 3 places to the left, so the exponent $n$ is 3.
The standard form is $\boxed{3.29302 \times 10^3}$.

b) 0.00342

It was moved 3 places to the right, so the exponent $n$ is -3.
The standard form is $\boxed{3.42 \times 10^{-3}}$.

c) 0.284

It was moved 1 place to the right, so the exponent $n$ is -1.
The standard form is $\boxed{2.84 \times 10^{-1}}$.

d) 397203

Move it to the left until there is only one non-zero digit before it.

It was moved 5 places to the left, so the exponent $n$ is 5.
The standard form is $\boxed{3.97203 \times 10^5}$.

2. Write the numbers whose standard form is:
To convert from standard form to an ordinary number, move the decimal point according to the exponent of 10. A positive exponent means moving right, and a negative exponent means moving left.

a) $3.5764 \times 10^3$

The number is $\boxed{3576.4}$.

b) $9.3816 \times 10^3$

The number is $\boxed{9381.6}$.

c) $9.002 \times 10^5$

Add zeros as needed.

The number is $\boxed{900200}$.

3. Use a calculator to find the square root of:

a) 483.93

The square root is approximately $\boxed{21.998}$.

b) 294.3

The square root is approximately $\boxed{17.155}$.