Perform each of the following calculations, and give an answer with the correct number of significant figures: a. $45.7 \times 0.034$ b. $0.00278 \times 5$ c. $\frac{34.56}{1.25}$ d. $\frac{(0.2465)(25)}{1.78}$ e. $\left(2.8 \times 10^4\right)\left(5.05 \times 10^{-6}\right)$ f. $\frac{\left(3.45 \times 10^{-2}\right)\left(1.8 \times 10^5\right)}{\left(8 \times 10^3\right)}$

What SI units are used for measuring the following quantities? For derived units, express your answers in terms of the six fundamental units. (a) Mass (b) Length (c) Temperature (d) Volume (e) Energy (f) Density

A doctor orders 5.0 mL of phenobarbital elixir. If the phenobarbital elixir is available as 30. mg per 7.5 mL, how many milligrams is given to the patient?

A doctor orders $5.0 mL$ of phenobarbital elixir. lf the pheno- barbital elixir is available as $30.$ mg per $7.5 mL$, how many milligrams is given to the patient?

a. Write an equality and two conversion factors for Greg’s serum iron level.
b. How many micrograms of iron were in the 8.0-mL sample of Greg’s blood?

a. At a local hospital, 35 babies were born. If 22 were boys, what percentage of the newborns were boys? Express your answer to the ones place.
b. An alloy contains 67 g of pure gold and 35 g of pure zinc. What is the percentage of zinc in the alloy? Express your answer to the ones place.
c. A collection of coins contains 15 pennies, 14 dimes, and 6 quarters. What is the percentage of pennies in the collection? Express your answer to the ones place.

Round off or add zeros to each of the following to give an answer with two significant figures: a. $3.2805 \mathrm{~m}$ b. $1.855 \times 10^2 \mathrm{~g}$ c. $0.002341 \mathrm{~mL}$ d. $2 \mathrm{~L}$

State the type of measurement in given of the following statements:
a. I put 12 L of gasoline in my gas tank.
b. My friend is 170 cm tall.
c. We are 385 000 km away from the Moon.
d. The horse won the race by 1.2 s.

Round off or add zeros to each of the following to give an answer with three significant figures: a. $56.855 \mathrm{~m}$ b. $0.002282 \mathrm{~g}$ c. $11527 \mathrm{~s}$ d. $8.1 \mathrm{~L}$

Write each of the following in scientific notation with two significant figures: a. $5000 \mathrm{~L}$ b. $30000 \mathrm{~g}$ c. $100000 \mathrm{~m}$ d. $0.00025 \mathrm{~cm}$

Round off each of the measurements in Problem $2.29$ to two significant figures.

State the number of significant figures in each of the following measured numbers:

a. 0.000 35 g

b. 2000 m

c. 2.0045 L

State the name of the unit in each of the following, and identify that unit as a metric/SI unit or not: a. $5.5 \mathrm{~mL}$ b. $45 \mathrm{~kg}$ c. 16 in. d. $25 \mathrm{~s}$ e. $22^{\circ} \mathrm{C}$

Round off each of the following measurements to three significant figures: a. $1.854 \mathrm{~kg}$ b. $88.0238 \mathrm{~L}$ c. $0.004738265 \mathrm{~cm}$ d. $8807 \mathrm{~m}$ e. $1.8329 \times 10^3 \mathrm{~s}$