rounding to decimal places?

Question

its my homework and i didnt understand in class,theres also a test on it tomorrow.please, please help

an example on the question sheet is

14.78 to 1 decimal place .what does it mean!!!!

Answer 1

Decimal places are how many numbers there are after the decimal point.

So, for example, 1.1 is a number to one decimal place.

If you have a long decimal, such as 6.53885493, then it is easier to read it by rounding. Rounding approximates the number.

How it works is that you take the number of decimal places you want and add one. So if you need to round it to 3 decimal places, go to the fourth number after the decimal point. If it's less than 5, then you can just take the first 3 numbers after the decimal point and ignore the rest and that's your answer.

If it's 5 or more, you have to add one to the third number after the decimal point and that's your answer.

So in the example above, it's 6.5 to 1 decimal place.That's because the second number after the decimal point is 3, so you don't have to add anything to the 5.

But if you're rounding to two decimal places, it's 6.54 because the third number is greater than 5. It works because if the digit is greater than 5, it means the overall number is actually closer to 6.54 than 6.53 so it's a better approximation.

So 14.78 to 1 decimal place is 14.8. It's just means it wants roughly the right answer without having to go to a huge number of decimal places.

Answer 2

Relax its a simple rule.
Decimal places is the amount of figures after the decimal point. Example: 6.278 is a figure given to 3 Decimal places because there are 3 figures after the decimal point.
Now, say you wanted to round the above figure to one decimal place. You look at the 2nd decimal number (in this case its a 7) and ask 'is that number 5 or greater'
If it is, then the 1st number (2) becomes a 3. You have 'rounded up' If it is below 5, then the 2 remains a 2.
The same rule applies to however many decimal places you want to go to.
If you wanted to take the above figure to 2 decimal places, look at the 3rd decimal figure and decide whether to go up 1 or stay put. Hope this helped. Let us know how you did

Answer 3

Well, I need to ask you a question in return? Is this elementary math or are you doing this in Chemistry or some such that is having you do significant figures?

The first being easier to explain, I'll start with that.

1.) If you are rounding decimal places, it's like rounding any other number. If it is 4 or less you round down, 6 or higher you round up, and if it is 5, then you round to which side will make it even.
As far as number of decimal places, usually your teacher will tell you what to round to, but is s/he doesn't, a good rule of thumb is just use the least number of places used in the problem. So if you had 1.43x2.543, you would only round 2 decimal places.

If it is in fact significat figures your working with, feel free to email me and I'll explain that :)

Answer 4

Right ok....the bbc are very good at explaining curriculum skills. Some links...

http://www.bbc.co.uk/skillswise/numbers/fractiondecimalpercentage/decimals/usingdecimals/

http://www.bbc.co.uk/skillswise/numbers/fractiondecimalpercentage/decimals/usingdecimals/factsheet4.shtml

Ok so 14.78 to one decimal place...

Step 1 - One decimal place it to the 7, so take 14.7 and look at the number after (8).

Step 2-Numbers that are 5 and over need to be rounded UP. Numbers under 5 need to be rounded DOWN.

Step 3- Round away...you should get 14.8 as you round '8' up and add on one unit.

I think the BBC can explain it better than me though!! X)

It may be a little tricky at first, but you will get the hang of it!

Good luck with your maths!

Answer 5

The answer 14.8 the way to do itis easy dont make it hard by looking to deep.eg. 7.67 the seven is more than 5 so is rounded up and puts one on the 6. 7.7 Its rounding up or down from 5 five or lower leave it out above five column in front goes up one.this can be used on any number eg. 14.47841. 1 is under 5 so goes to 14.4784. 4 again low 14.478. 8 high add 1 to column in front of it 14.48. 8 high so 14.9 is the answer. hope that helps in any way good luck on test

Answer 6

well, say you've got a number with several decimal places eg. 1.548 and you want to round it to 2 decimal places, you would count along 2 (1.54) and if the last number (8) is above 5 then you round the 4 up (1.55)
hope this helps

Answer 7

14.78
To round to the first decimal place means to round the number up to the first number after the decimal, 7. Therefore if you were to round this up to the first decimal place the number would be 14.8 (because the 8 tells us to round the seven up).

Answer 8

To round off decimals:

Find the place value you want (the "rounding digit") and look at the digit just to the right of it.

If that digit is less than 5, do not change the rounding digit but drop all digits to the right of it.

If that digit is greater than or equal to five, add one to the rounding digit and drop all digits to the right of it.

From:
www.math.com/school/subject1/lessons/S1U1L3GL.html

This site also has a practice page:
www.math.com/school/subject1/practice/S1U1L3/S1U1L3Pract.html

Answer 9

If the second digit is 5 or more round the number to the left up one

If the second digit is below 5 leave the digit to the left alone

Hope this helps.......

Answer 10

Computers and accountants round decimal places in many ways but people normally use the following standard:

If the last number is 1,2,3 or 4 then round down to 0, if the if it is 5,6,7,8,9 then round up.

e.g.

2.5 rounds up to 3
1.2 rounds down to 1

When there are several numbers then you need to repeat this process for each digit
e.g.
3.14159 rounds upto 3.1416
which rounds upto 3.142
which rounds down to 3.14
which rounds down to 3.1
which rounds down to 3

If you are told to round to 2 decimal places then you can simply do this but stop sooner

e.g. 3.14159 rounded to 2 decimal places would be 3.14