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how many s.f or d.p watch

1. How do you decide how many s.f or d.p do you decide to leave your answer too?

As its pointless losing silly marks for inaccurate answers.

Thanks for all help
2. Depends what you're doing, ie maths or physics.

If you're doing maths and you end up with an answer like leave it as that.

If you're doing something like Simpson's rule and they don't give you the number of figures to give, go for 3sf I'd say, maybe 4 (depending on how many steps you do in the method).

If you're doing physics, then go to 1 sf less than the most inaccurate measurement they give you, in that if they give you measurements with 3sf in all of them, only go to 2. Beyond that the errors are too large for your last digit to many anything.
3. (Original post by AlphaNumeric)
Depends what you're doing, ie maths or physics.

If you're doing maths and you end up with an answer like leave it as that.

If you're doing something like Simpson's rule and they don't give you the number of figures to give, go for 3sf I'd say, maybe 4 (depending on how many steps you do in the method).

If you're doing physics, then go to 1 sf less than the most inaccurate measurement they give you, in that if they give you measurements with 3sf in all of them, only go to 2. Beyond that the errors are too large for your last digit to many anything.
My physics teacher always told me to quote your answer to the same number of sig figs as the least accurate piece of data in the calculation.

E.g. R = V/I = 23V/2.34A = 9.8 ohms
4. I suppose if it's only one reading, then the same is fine. If you've two or more than when you combine the errors, it'll make the last sig fig less important
5. (Original post by Widowmaker)
My physics teacher always told me to quote your answer to the same number of sig figs as the least accurate piece of data in the calculation.

E.g. R = V/I = 23V/2.34A = 9.8 ohms
Agree.

Nevermind decimal places.

It's significant figures that matters in physics. There is no point quoting more significant figures than that of the least accurate piece of data.

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