# How is this inaccurate?

• Oct 2nd 2013, 01:50 AM
Connie
How is this inaccurate?
Hello,

I've been confronted by a parent who stated that my statements below are wrong

Use four digit whole numbers with two decimal places..
4567.89 rounded equals 4567.9 then 4568.0

9876.54 rounded equals 9876.50 then 9877.0
• Oct 2nd 2013, 02:58 AM
Plato
Re: How is this inaccurate?
Quote:

Originally Posted by Connie
I've been confronted by a parent who stated that my statements below are wrong
Use four digit whole numbers with two decimal places..
4567.89 rounded equals 4567.9 then 4568.0

9876.54 rounded equals 9876.50 then 9877.0

I see nothing wrong with the statements.
But all depends upon definition. How do you define rounding?
It appears that by round you mean to the closest integer.
If that is the case, and the decimal part is at least half round up.
• Oct 2nd 2013, 03:04 AM
Connie
Re: How is this inaccurate?
Quote:

Originally Posted by Plato
I see nothing wrong with the statements.
But all depends upon definition. How do you define rounding?
It appears that by round you mean to the closest integer.
If that is the case, and the decimal part is at least half round up.

Thank you for your prompt response.

The individual stated that my use of the word equals was wrong.
Then they commented that the statement '4567.89 rounded equals 4567.9' was incorrect.

To put this in context this was the text that I sent home:
Your maths mission for this week is to practise and improve your skills at rounding numbers to the nearest 1, 10, 100, or 1000.

Remember, when using whole numbers, look at the units. If the unit value equals 0 or 1 or 2 or 3 or 4 (less than 5) then round down:
72 rounded equals 70 because the 2 units is less than 5
654 rounded equals 650 because the 4 units is less than 5
9753 rounded equals 9750 because the 3 units is less than 5

If the unit value equals 5 or 6 or 7 or 8 or 9 (more than 4) then round up:
56 rounded equals 60 because the 6 units is more than 4
345 rounded equals 350 because the 5 units is more than 4
4567 rounded equals 4570 because the 7 units is more than 4

If you want a challenge then use four digit whole numbers with two decimal places.
4567.89 rounded equals 4567.9 then 4568.0
9876.54 rounded equals 9876.50 then 9877.0
• Oct 2nd 2013, 03:34 AM
Plato
Re: How is this inaccurate?
Quote:

Originally Posted by Connie
Thank you for your prompt response.
The individual stated that my use of the word equals was wrong.
Then they commented that the statement '4567.89 rounded equals 4567.9' was incorrect.
To put this in context this was the text that I sent home:
Your maths mission for this week is to practise and improve your skills at rounding numbers to the nearest 1, 10, 100, or 1000.
Remember, when using whole numbers, look at the units. If the unit value equals 0 or 1 or 2 or 3 or 4 (less than 5) then round down:
72 rounded equals 70 because the 2 units is less than 5
654 rounded equals 650 because the 4 units is less than 5
9753 rounded equals 9750 because the 3 units is less than 5
If the unit value equals 5 or 6 or 7 or 8 or 9 (more than 4) then round up:
56 rounded equals 60 because the 6 units is more than 4
345 rounded equals 350 because the 5 units is more than 4
4567 rounded equals 4570 because the 7 units is more than 4
If you want a challenge then use four digit whole numbers with two decimal places.
4567.89 rounded equals 4567.9 then 4568.0
9876.54 rounded equals 9876.50 then 9877.0

Frankly, I would avoid both the words rounded and equals.
I would ask, "what is the closest integer?".
On the other hand, the statement "The rounded form of 456.9 equals 457" is a very clear use of both words.
• Oct 2nd 2013, 04:00 AM
aldrincabrera
Re: How is this inaccurate?
Can we say "72 rounded off is equal to 70?"
• Oct 2nd 2013, 04:12 AM
Plato
Re: How is this inaccurate?
Quote:

Originally Posted by aldrincabrera
Can we say "72 rounded off is equal to 70?"

No because 72 is an integer.
Again, what is the working definition of "to round"?
• Oct 2nd 2013, 04:16 AM
aldrincabrera
Re: How is this inaccurate?
Per merriam-webster round means "to express as a round number —often used with off." I am also confused with merriams example : "11.3572 rounded off to two decimal places becomes 11.36."
• Oct 2nd 2013, 06:40 AM
Connie
Re: How is this inaccurate?
Thanks for those that have responded.

So, have I been mathematical incorrect in using the term equals within the sentence:

4567.89 rounded equals 4567.9 then 4568.0
• Oct 2nd 2013, 06:47 AM
topsquark
Re: How is this inaccurate?
Quote:

Originally Posted by Connie
Thanks for those that have responded.

So, have I been mathematical incorrect in using the term equals within the sentence:

4567.89 rounded equals 4567.9 then 4568.0

Out of curiosity why are you rounding in two steps? You can round 4567.89 to 4568 in one step.

-Dan
• Oct 2nd 2013, 11:17 AM
Connie
Re: How is this inaccurate?
Quote:

Originally Posted by topsquark
Out of curiosity why are you rounding in two steps? You can round 4567.89 to 4568 in one step.

-Dan

This homework is for children of age 9. In class we were practising the method of rounding and recorded their answers in this format:

1234.56
1234.60
1235.0
1240
1200
1000

This is mathematically acceptable, isn't it?
• Oct 2nd 2013, 11:56 AM
SlipEternal
Re: How is this inaccurate?
Quote:

Originally Posted by Connie
This homework is for children of age 9. In class we were practising the method of rounding and recorded their answers in this format:

1234.56
1234.60
1235.0
1240
1200
1000

This is mathematically acceptable, isn't it?

Well, if they rounded to the nearest 10 at the beginning, they would have gotten 1230 instead of 1240.
• Oct 2nd 2013, 11:56 PM
Connie
Re: How is this inaccurate?