Step by step
The question
Question: estimate 286 ÷ 0.52.
To estimate means to find about how big the answer is.
We make every number easy first.
1 Round to 1 significant figure
We round each number to 1 significant figure: only its first figure stays.
286: the first figure is 2.
The next digit is 8, 5 or more, so we round up: 300.
0.52: the first figure is 5.
The next digit is 2, 4 or less, so we round down: 0.5.
2 Work it out
So the answer is about 300 ÷ 0.5.
Now it is easy to work out.
Careful!
We changed the numbers.
So we write ≈, about, not =.
300 divided by 0.5 is 600.
To divide by 0.5, we move the point in both numbers 1 place: 3000 divided by 5.
That is 600.
So the answer is about 600.
3 Check
Let's check with a calculator.
The exact answer is about 550.
That is close to 600.
So the estimate is good!
Let's look back.
First: round to 1 significant figure.
Then: work it out.
Last: check.