Calculation ????

ed sautter

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238
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Cortland NY
I have done the math and know the final number but with the hand held caclualtor it doesn't come up correctly. I've tried three or four others as well as some online calculators but it still comes up wrong.

Here the calculation and you give it a try. 111 7/8 - 52 15/16 = ?

I figure the calculators are rounding but why? Wouldn't it be programed to give exact number regardless? Maybe someone knows why.
 
That is the incorrect number. If that's the case it would 58 15/16. There's a difference between 7/8 and 15/16 that isn't being calculated correctly. I deal with the smallest of fractions in the CAD programing job I have and find this unexceptable. I can and did do the math to figure this out but with the hand held it comes up wrong every time.
 
That is the incorrect number. If that's the case it would 58 15/16. There's a difference between 7/8 and 15/16 that isn't being calculated correctly. I deal with the smallest of fractions in the CAD programing job I have and find this unexceptable. I can and did do the math to figure this out but with the hand held it comes up wrong every time.

Uhhh, Ed... If you do the math MANUALLY ( like, on paper :eek: ) the answer IS 58 and 15/16". 15/16 is 0.9375

111-7/8 = 111-14/16 = 110-30/16

110-30/16 minus 52-15/16 = 58-1/16 (or 58.9375)

What answer (that you're assuming to be correct) are you getting?
 
The fractional calculator app on my phone says it's 58 15/16. What number are you getting that's incorrect, Ed?
 
Wish I knew what he was doing wrong cause I come up with 58-15/16" also but I always use the decimal equivalent of fractions whenever I use a calculator.
 
Wish I knew what he was doing wrong cause I come up with 58-15/16" also but I always use the decimal equivalent of fractions whenever I use a calculator.

I even tried using the equation: (111+(7÷8)) - (52+(15÷16)) and I got the same answer, so I can't see where there's a "conversion' error anywhere.

Ed???
 
Ok it's been a long day guys. I did the math one more time and who's the one with egg on their face, me. Guys I'm wrong. I was spliting the difference between 15/16 and 7/8. I had the number as 58.90625. After doing the math again I was indeed wrong. Still looks funny to me but sorry for the confusion. The calculator was right. Just seams strange that after calculating the end number would be 15/16 again go figure.
 
Ed, you're in luck! The International Society for Egg-Faced Mathematicians is having their recruitment drive this month. (As a long-time member, I get the newsletter...that's how I know about the drive.)

220, 221, whatever it takes.......... :)

OK, that made me laugh. :rofl:
 
Uhhh, Ed... If you do the math MANUALLY ( like, on paper :eek: ) the answer IS 58 and 15/16". 15/16 is 0.9375

111-7/8 = 111-14/16 = 110-30/16
110-30/16 minus 52-15/16 = 58-1/16 (or 58.9375)

What answer (that you're assuming to be correct) are you getting?

I did the same thing manually. I came up with the same answer. I did it again using my Casio hand held and arrived at the same answer. Since the Casio is in decimal I had to use 7/8---that is 7 divided by 8 to convert it to decimal= 0.875 and 15 divided by 16 to get 0.9375. I obtained the same answer both ways. 58.9375.

Back in the days of my physics classes we had specific rules for rounding numbers. I don't think I have used those rules since, therefore they are gone. This is a good example of, "Don't get old, your brains leak out." If you follow the rules the rounding works accurately. If the rules are not followed you get some answers that are good enough for government work but not for launching a rocket to the moon.

I am sure that any calculator has programming for how to round-off. I sincerely doubt that the programming is much more accurate than needed for the calculator's anticipated use.

Enjoy,

JimB
 
This is precisely what makes me use millimeters! I use fractional right up until it is time for math. Sometimes. All my rules are fractional/metric. I get the best of both worlds.
 
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