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Eight inches of heavy, wet snow are equivalent to four inches of rain. Estimate the water content in 17 inches of heavy, wet snow.

Ok I get 8.4 as the answer for this problem but by calculator I get 8.5 and the answer that is right is 8.5. I'm not sure what I'm doing wrong since I do the same steps on the calculator as when I'm writing it by hand.

$$17 \cdot 4 = 68, 68/8 = 8.5 $$

When I divide by hand I get 8.4 every time 8 goes into 68 8 times with a remainder of 4.

what should I be doing to get the correct answer?

Thomas Andrews
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PostMagne
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  • To whoever downvoted this question: you are wrong. This site is intended for people learning mathematics, and this question fits perfectly. – 5xum Apr 27 '15 at 20:32
  • The remainder of $4$ is not the same as $0.4$. It is $\frac{68}8 = 8 + \frac{4}{8} = 8.5$. – Thomas Andrews Apr 27 '15 at 20:34
  • @5xum When you have a question about division, you should show your long division seeing as the problem came in doing the actual calculation. We are left guessing as to what Ops mistake was....I have no problem with elementary problems, however I do object to absence of relevant context. I assume now that I've posted my criticism, I can hold my opinion in peace? – Zach466920 Apr 27 '15 at 20:49
  • @Zach466920 You can, but I still think you are wrong. The OP told, to the best of his ability, what his problem was. It was clear both to me and to at least one other experienced user what the problem was: the confusion between remainders and decimal notation, and this is easily understood from OPs question. He made it perfectly clear that he calculated $68/8$ to be equal to $8$ with $4$ remaining, and it was clear that he thought that this should then be $8.4$. To the best of his ability, he gave us everything he should. – 5xum Apr 27 '15 at 21:24
  • @5xum if you insist, however you should consider his history of neglecting to show work. Look here and another. This is less about not understanding the question, as all of his questions are obvious for an experienced user to answer, its more about ensuring the site is not merely a do my work for me site. P.S. you've now seen all of his questions on this site. – Zach466920 Apr 27 '15 at 21:30

2 Answers2

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The remainder is $4$, but $8.5$ does not mean that the remainder when dividing by $8$ is equal to $5$.

The decimal point means that whatever number follows is the number of tenths in the answer, so $8.5=8+\frac{5}{10} = 8 + \frac12$. This is the correct answer because, when dividing $68$ by $8$, you get $8$ and a remainder of $4$, and if you divide that remainder by $8$, you get $\frac48 = \frac12$, meaning that $68 / 8 = 8 + \frac42 = 8 + \frac12 = 8.5$

5xum
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(I'll write out the long division "European" style; I have no idea how to even remotely typeset American style )

 68 : 8 = 8.5
 64      
  40
  40
   0

Note that the remainder $4$ is not simply carried to the result as decimal digit; instead, to go one digit further, we append the next digit of $68.\color{red}0$ and divide $40$ by $8$

Hagen von Eitzen
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