Today I worked 6 hours [I Want To Be Better At Math]

I assembled 10 pieces in 3hrs 25min. Or 205 minutes.

10 pieces ÷ 205min = 0.0487804

Soo how many pieces did I do per hour?

If i would have done 10 pieces in 5 hours then the answer would be 2 pieces per hour because 10 ÷ 5hrs. = 2.

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ArishMell · 70-79, M

You've put the division the wrong way round.

10 pieces in 205 minutes is (205 / 10) minutes each, not 10 / 205; so 20.5 minutes per piece. 20min 30s.

So 2 complete per hour; plus a third not quite finished. Three in 1h:1m:30s. Work just a little more efficiently and you might do exactly three an hour!

twiigss · M

@ArishMell Maybe I'm taking words and making them too literal then.

I always thought you would say, for example, if I did 10 pieces in 30 minutes, isn't the correct thing to say, Ten divided up into thirty minutes? That's how I always say it anyways, and that makes me think 10 / 30. But you're saying you take 30 minutes and divide by 10 pieces?

ArishMell · 70-79, M

@twiigss Oh, I do that too, occasionally!

Maths was never my strong point. I could see where you'd gone wrong there, but anything much more advanced and abstract becomes too hard for me.

Yes - that's right. You know how long it takes to make a number of items, so to find how long 1 takes, divide the total time by the total number of items.

You can prove it to yourself by reversing the question. In fact it's a very good way to make sure of having done the original calculation properly.

So, reversing, and simplifying your numbers a bit, if it takes you exactly 20 minutes to make 1 item, how long will you take to make 3?

Then it's 20 X 3 = 60 minutes = I hour.

And 10 items? 10 X 20 minutes = 200 minutes = 3 h: 20 mins.