MHB How to Calculate Percent Correct: 87.5% - Understanding Decimals and Rounding

[OMGMathPLS]

On a quiz of 64 questions a tester got 56 correct. What percent were correct?
(Write a number only, no % sign, rounded to one decimal place.)

The correct answer was 87.5

But I wrote 88 because I rounded to one decimal place up. Why is that wrong.

If you round up you round up when it lands on 5 or up. And go down if its on 4 or below.

Is the decimal place 1/tenth of a decimal place? Did they mean a whole digit decimal place? Why is it left exactly how it is 87.5 and that is the correct answer?

When you put it into the calculator 56/64 *100 it comes out to 87.5 so why was there a need to even put ROUND UP TO A DECIMAL PLACE if that wasn't going to be happening to begin with? Why did the professor do this?

 

[ineedhelpnow]

the question says round to one decimal place (Blush) 1 decimal place means 87.5. its not that your answer is "wrong" but your professor wants you to become familiar with rounding decimals and wants you to understand what decimal places are.

 

[MarkFL]

Perhaps this instruction regarding rounding was meant for a group of problems, in the event that a decimal expression representing the percentage had more than one digit to the right of the decimal point.

When told to round to one decimal place, if there is only one such place, then no rounding is required.

 

[OMGMathPLS]

I know that but nothing changed. So they put superfluous instructions that only served to confuse me. If they didn't put that to round up shenannigans I wouldn't have got it wrong because I would have looked at it and just left it alone.

 

[ineedhelpnow]

yes but your instructor WANTS you to understand what one decimal place is. he wants you to think on the quiz. i understand though. sometimes i have instructors that take off points even though the answer was right and when i look back its only because i didnt round right or box the answer or something dumb like that.

 

[MarkFL]

I know that but nothing changed. So they put superfluous instructions that only served to confuse me. If they didn't put that to round up shenannigans I wouldn't have got it wrong because I would have looked at it and just left it alone.

Let me ask you...how would you round 87.51 to one decimal place?

 

[OMGMathPLS]

Ok, can we please break it down. What does it mean to round to one decimal place?

For example:

.6 becomes 1 right?

and 21.3 becomes 21 right?

That's what I thought it meant.

Where is the decimal place?I would round 87.51 to 87.5

 

[ineedhelpnow]

one decimal place:

0.125 rounds to 0.1
1.378 rounds to 1.4
2.64797546413246545113 rounds to 2.6

 

[OMGMathPLS]

Ok, so round to one decimal place means

round and leave one number after the .

.3

.4

.6 etc?

 

[MarkFL]

Ok, can we please break it down. What does it mean to round to one decimal place?

For example:

.6 becomes 1 right?

and 21.3 becomes 21 right?

That's what I thought it meant.

Where is the decimal place?I would round 87.51 to 87.5

Rounding to one decimal place means to round to the nearest tenth. So, 0.6 remains as 0.6 and 21.3 remains as 21.3. You did round 87.51 correctly to 87.5. :D

 

[ineedhelpnow]

:) exactly

 

[OMGMathPLS]

Ok, thank you. That's why it was wrong. Now I understand. It makes sense thank you/

 

[ineedhelpnow]

it Would have been 88 if your professor said to round to the nearest whole number or to the nearest integer.