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Round 0.07049 to 3 significant figures

Step by step, with the reason for every step · Significant figures and estimating · Foundations

Step by step

The question

Question: round 0.07049 to 3 significant figures.

Round 0.07049 to 3 significant figures

1 Find the first significant figure

The first significant figure is the first digit that is not 0.

In 0.07049, it is 7.

= 0.07049

The zeros in front only hold the place.

They are not counted.

0s in front: not counted
significant figures: counted from
the first digit that is not 0

2 Count the figures

We count 3 figures from there: 7, 0, 4.

The 3rd figure, 4, is in the ten-thousandths place.

So we round to the nearest ten-thousandth.

= 3rd figure 4 → the ten-thousandths place

3 Look at the next digit

Now we look at the next digit to the right.

It is 9.

5 or more: we round up.

4 or less: we round down.

9 is 5 or more, so we round up.

= 9 is 5 or more → round up
5 or more → up: digit + 1
4 or less → down: digit stays

4 See it on a number line

0.07049 is closer to 0.0705.

5 Keep the size

We stop after the 3rd figure.

So 0.07049 is about 0.0705.

= 0.07049 ≈ 0.0705

Careful!

The zeros in front are not counted.

But they stay in the answer.

They hold the place.

Careful: the 0s in front stay: 0.0705

So 0.07049 to 3 significant figures is 0.0705.

6 Check

Let's check.

0.0705 has 3 significant figures: 7, 0, 5.

0.0705: figures 7, 0, 5 → 3 s.f.

And it is close to 0.07049.

So the answer is right!

0.07049 ≈ 0.0705: the same size

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.

Answer
Careful: the 0s in front stay: 0.0705

Your turn

Try this one yourself, then check:

Round 0.10074 to 3 significant figures
Show the answer
0.10074 ≈ 0.101

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