Step by step
The question
Question: estimate √35 to the nearest tenth.
The square root of 35 is the number that times itself makes 35.
Careful!
The square root is not half.
17.5 times 17.5 is 306.25, far more than 35.
1 List the squares
First, the square numbers near 35.
4 times 4 is 16.
5 times 5 is 25.
6 times 6 is 36.
7 times 7 is 49.
2 Find where it fits
35 is between the squares 25 and 36.
A bigger number has a bigger square root.
So √35 is between √25 and √36.
√25 is 5.
√36 is 6.
So √35 is between 5 and 6.
3 Which is closer
35 is 10 more than 25, and 1 less than 36.
1 is less.
So 35 is closer to 36, and √35 is closer to 6.
4 Try tenths
√35 is a bit less than 6.
So we try 5.9 and so on, and square each one.
5.9 times 5.9 is 34.81.
That is less than 35: too small.
So √35 is between 5.9 and 6.0.
5 Pick the nearest tenth
35 is 0.19 more than 34.81, and 1 less than 36.
So it is closer to 34.81.
So √35 is about 5.9, to the nearest tenth.
6 Check
Let's check with the number halfway: 5.95.
5.95 times 5.95 is 35.4025, more than 35.
So √35 is below 5.95.
To the nearest tenth, it is 5.9.
The answer is right!
Let's look back.
First: list the squares.
Then: find where it fits.
Then: which is closer.
Then: try tenths.
Then: pick the nearest tenth.
Last: check.