# Long division answer diffrent to calculator

• Nov 15th 2008, 08:22 AM
EvoUK
Long division answer diffrent to calculator
Hi guys,

I've got a bit of a problem with my long division - I was hoping you could help me with please. I keep getting a slight variation between my results on paper and the one I get from the calculator.

Question: If a/c flies 764 miles in 78 mins how fast is it moving?

S=D/t

So the equation I'd use is

S = (764 / 78) x 60 (to convert the minutes to hours).

The result I got from long division is 578MPH...
However using a calculator, the answer I got was more like 587MPH..

I've noticed this problem with pretty much any equation I do using long division.. The answer is always slightly different to that of the calculator mainly after the decimal point.

Before the x60 conversion, the decimal I had from long division (764 / 78 = 9.62) but the calculator's answer was more like 9.79.. which seems to make all the diffrence.

No matter what I do, I cant seem to replicate this answer using simple long division.

Am I doing this all wrong?
• Nov 15th 2008, 08:29 AM
Shyam
Quote:

Originally Posted by EvoUK
Hi guys,

I've got a bit of a problem with my long division - I was hoping you could help me with please. I keep getting a slight variation between my results on paper and the one I get from the calculator.

Question: If a/c flies 764 miles in 78 mins how fast is it moving?

S=D/t

So the equation I'd use is

S = (764 / 78) x 60 (to convert the minutes to hours).

The result I got from long division is 578MPH...
However using a calculator, the answer I got was more like 587MPH..

I've noticed this problem with pretty much any equation I do using long division.. The answer is always slightly different to that of the calculator mainly after the decimal point.

Before the x60 conversion, the decimal I had from long division (764 / 78 = 9.62) but the calculator's answer was more like 9.79.. which seems to make all the diffrence.

No matter what I do, I cant seem to replicate this answer using simple long division.

Am I doing this all wrong?

• Nov 15th 2008, 08:32 AM
EvoUK
Can you replicate that answer using long division alone?
• Nov 15th 2008, 10:35 AM
Shyam
Quote:

Originally Posted by EvoUK
Can you replicate that answer using long division alone?

$= \left( {764 \div 78} \right) \times 60 \hfill \\$

${\text{Long division is}} \hfill \\$

$78{\text{ }}\overline {){\text{ }}764{\text{ }}(} {\text{ }}9.79487179 \hfill \\$

${\text{ }}\underline {{\text{ 702 }}} \hfill \\$

${\text{ 620}} \hfill \\$

${\text{ }}\underline {{\text{ 546 }}} \hfill \\$

${\text{ 740}} \hfill \\$

${\text{ }}\underline {{\text{ 702 }}} \hfill \\$

${\text{ 380}} \hfill \\$

${\text{ }}\underline {{\text{ 312 }}} \hfill \\$

${\text{ 680}} \hfill \\$

${\text{ }}\underline {{\text{ 624 }}} \hfill \\$

${\text{ 560}} \hfill \\$

${\text{ }}\underline {{\text{ 546 }}} \hfill \\$

${\text{ 140}} \hfill \\$

${\text{ }}\underline {{\text{ 78 }}} \hfill \\$

${\text{ 620}} \hfill \\$

${\text{ }}\underline {{\text{ 546 }}} \hfill \\$

${\text{ 740}} \hfill \\$

${\text{ }}\underline {{\text{ 702 }}} \hfill \\$

${\text{ 38}} \hfill \\$

${\text{Now,}} \hfill \\$

$9.79487179 \times 60 = 587.6923074 \simeq 587.69 \hfill \\
$
• Nov 15th 2008, 02:12 PM
HallsofIvy
Yes, and that is what the calculator gave you! You said before:
Quote:

The result I got from long division is 578MPH...
Obviously, you divided incorrectly the first time.