# Question #9f7af

##### 1 Answer

The number must be rounded to three significant figures.

#### Explanation:

The key here is the **operation** that you perform in order to get the answer.

In this particular case, you can get the volume of the aquarium by **multiplying** its length, its width, and its height, i.e. you can treat the aquarium as a *rectangular prism*.

#V_"aquarium" = "12.9 in" xx "7.67 in" xx "4.11 in"#

#V_"aquarium" = "406.65573 in"^3#

Now, the thing to remember about **multiplication** and **division** is that the result of these operations must always be rounded to the number of sig figs present in the measurement that has the **least number** of sig figs.

You have

#"12.9 " -> " 3 non-zero digits = 3 sig figs"# #"7.67 " -> " 3 non-zero digits = 3 sig figs"# #"4.11 " -> " 3 non-zero digits = 3 sig figs"#

In your case, all three measurements have **sig figs**, so you can say that their *product* must be rounded to **sig figs**.

In order to round the answer to **sig fig** and compare it to **add**

If the

#stackrel(color(blue)(1))(4)stackrel(color(blue)(2))(0)stackrel(color(blue)(3))(6). stackrel(color(blue)(4))(6)5573#

In your case, you have

#6 >= color(red)(5) -># the#color(blue)("4th"# sig figs is greater than or equal to#color(red)(5)#

This means that you will add

#6 + 1 = 7#

and drop the rest of the figures *and* the decimal point.

#stackrel(color(blue)(1))(4)stackrel(color(blue)(2))(0)stackrel(color(blue)(3))(7). color(red)(cancel(color(black)(65573)))#

This means that you have

#V_"aquarium" = "12.9 in" xx "7.67 in" xx "4.11 in" = "407 in"^3#

The answer is rounded to three **sig figs**.