# How do you round 1,566,311 into 3 significant figures?

##### 1 Answer

#### Explanation:

So, you know that you must round this number

#1,566,311#

to **significant figures**. The first thing to do here is to start at the first figure of the number and count **figures** as you move toward the last figure of the number.

In your case, you should end up on

#stackrel(color(blue)(1))(1), stackrel(color(blue)(2))(5) stackrel(color(blue)(3))(color(red)(6))6,311#

Now, the trick here is to look at the figure that follows the **round up**. On the other hand, if this figure is smaller than **round down**.

#"for a certain figure: " {("if" >= 5 -> "round up"), ("if" < 5 -> "round down") :}#

In this case, the figure that follows

#stackrel(color(blue)(1))(1), stackrel(color(blue)(2))(5) stackrel(color(blue)(3))(color(red)(6))color(darkorange)(6),311#

Since

#color(darkorange)(6) >= 5#

you will have to **round up** by adding

#color(red)(6) " "stackrel(color(white)(acolor(darkgreen)("rounded up")aaa))(->) " "color(red)(7)#

To finish rounding up the initial number, replace all the figures that follow

#stackrel(color(blue)(1))(1), stackrel(color(blue)(2))(5) stackrel(color(blue)(3))(color(red)(6))color(darkorange)(6),311 " "stackrel(color(white)(acolor(purple)("rounded to 3 sig figs")aaa))(->)" " stackrel(color(blue)(1))(1), stackrel(color(blue)(2))(5) stackrel(color(blue)(3))(color(red)(7))0,000#