Zeros at the end of a number? (after decimal point)?

Question

My teacher sais that if you round for example 12.340012132 to the ten-thousandths you have to keep the zeros after 12.34, making it 12.3400 instead of just 12.34

Is this how you're supposed to do it?

Answer 1

Your teacher is wrong.///

Answer 2

no, your teacher can't be right, because then you would just have to keep adding zeros after the 4

ex- 12.340000.....

Answer 3

If you are using the so called system of "significant figures," or "sig figs," then yes, this is how you are supposed to do it. The idea is that by keeping the zeros you are indicating that the number is accurate to the ten-thousandths place. If you just wrote 12.34 it would look as though your number is only accurate to the one-hundredths.

Answer 4

That's correct.  

any zeros after, or to the right of the decimal point  are significant.  

the zeros to the left of the decimal points are only significant when:

   a>  they are between numbers other than zero.  Ex:   3004

   b>  they have a bar over them specifying that they are significant , and not just place holders.

Answer 5

Yes. It may seem redundant but the purpose of this is to relay the message that throughout the problem you wished all answers to be expressed in ten thousandths.  

Answer 6

The number of decimal places implies an accuracy of the number.

12.34 implies you aren't any more accurate than .005

12.3400 implies you're accurate to .00005

yes, the trailing zeros are important and necessary

Answer 7

That's how you do it.

The problem says that you must round to the TEN-THOUSANDTHS, so you MUST keep the zeros, out to the ten-thousandsths place.

'12.34' is read as "twelve and thirty-four one-hundreths"

'12.3400' is read as "twelve and three-thousand four-hundred ten-thousandths"