# How do you round each number to four significant figures? 0.004384010 cm and 431,801 kg?

##### 2 Answers

#### Explanation:

Start counting significant figures from the first non-zero digit from the left.

The answers are 0.004 384 cm and 431 800 kg.

#### Explanation:

Here are the four rules you need.

- All
#color (red)("non-zero digits")# **are significant**. #color(red)"Inside zeroes"# (zeroes between significant digits)**are significant**.#color(red)("Trailing zeroes in the decimal portion")# of a number**are significant**.- If the first digit to be dropped is
#color(red)("less than 5")# ,**drop it**and all the digits to the right of it.

**0.004 384 010 cm**

The three leading zeroes are not significant, but the inside zero and the trailing zero are significant.

There are 7 significant figures.

The first 4 significant figures are 4384, so the first digit to be dropped is 0.

We therefore drop it and all the following digits.

To 4 significant figures,

**431 801 kg**

I am assuming that your comma is a thousands separator.

The inside zero is significant, so there are 6 significant figures.

The first 4 significant figures are 4318, so the first digit to be dropped is 0.

We therefore drop it and the following 1 and replace them with zeroes.

To 4 significant figures,