# How many significant figures are there in the number 1008500?

##### 1 Answer

#### Explanation:

The first thing to look for when deciding how many **significant figures** you have in a value is the *number of non-zero digits* it contains.

*Non-zero digits* are **always** significant, so right from the start you know that your number will contain *at least* as many significant figures as the number of non-zero digits it contains.

In this case, you have

Now, your number also contains **two sandwiched zeros**. By definition, a *sandwiched zero* is a zero that **follows** and is **followed by** at least one non-zero digit. Sandwiched zeros are **always** significant.

In your case, you have

#1color(red)(00)8500 -># two sandwiched zeros, significant

Here two zeros follow

Finally, your number also contains **two trailing zeros**. Trailing zeros are zeros that follow at least one non-zero digit and **are not** followed by other non-zero digits.

When trailing zeros **do not** follow the decimal point, they are **not significant**. In your case, you have

#10085color(purple)(00) -># two trailing zeros, NOT significant

Therefore, you can say that your number has **significant figures**

#1color(red)(00)85color(purple)(00) -> { (3color(white)(a) "non-zero digits, signifcant " color(green)(sqrt())), (color(red)(2)color(white)(a)"sandwiched zeros, significant "color(green)(sqrt())), (color(purple)(2)color(white)(a)"trailing zeros, NOT significant "color(red)(xx)) :}#