# The number 40 has how many significant figures?

Apr 18, 2017

$1$

#### Explanation:

It has one because the $4$ is the significant digit and the $0$ doesn't count. However, if you had $40.0$, you would have three, because the $0$ after the decimal point and the $4$ count and the numbers between the significant digits also count.

Apr 18, 2017

There is only $1$ significant figure in the number $40.$
Since there is no decimal point in the number, the trailing zero is not significant. Therefore the number $40$ has only $1$ significant figure.