Step by step
The question
Question: round 47,386 to 3 significant figures.
1 Find the first significant figure
The first significant figure is the first digit that is not 0.
In 47,386, it is 4.
2 Count the figures
We count 3 figures from there: 4, 7, 3.
The 3rd figure, 3, is in the hundreds place.
So we round to the nearest hundred.
3 Look at the next digit
Now we look at the next digit to the right.
It is 8.
5 or more: we round up.
4 or less: we round down.
8 is 5 or more, so we round up.
4 See it on a number line
47,386 is closer to 47,400.
5 Keep the size
The places after the 3rd figure become 0.
The zeros keep the size: 47,400 is close to 47,386.
Careful!
474 is much smaller than 47,386.
The zeros keep the number the right size.
So 47,386 to 3 significant figures is 47,400.
6 Check
Let's check.
47,400 has 3 significant figures: 4, 7, 4.
And it is the same size as 47,386: 5 digits before the point.
So the answer is right!
Let's look back.
First: find the first significant figure.
Then: count the figures.
Then: look at the next digit.
Then: see it on a number line.
Then: keep the size.
Last: check.