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[dolphy-chan]

Hihi,

Just a quick question for rounding decimals. When it doesn't specify the amount of decimals or sig fig to round to, how many is advised? Or rather what do you usually do? 3 sig fig? To 2 decimal points? Usually I do about 1-2 decimals when a question doesn't specifies, but sometimes when I do it that way, I get the question wrong because it gives an answer which is a higher or lower number than the one I came up with...

Okay...yea... that was probably confusing or something like that,

ttyl~!

Xxdolphy~!

 

[PC]

My advice is:

1. Make sure you never round off until the very last line of your working. It's certainly a hassle writing down a string of decimals from your calculator in your working, but don't be lazy. Just do it. And in most cases you don't have to retype them back in, you can use the ANS button on the calculator.

2. When rounding off, make sure you do it properly. It's a common error in HSC exams according to the notes from the marking centres each year. Practice with "decimal places" and "significant figures".

3. In the majority of questions, you'll be told how many decimal places (or significant figures) to round off to. Don't make up your own rules and make up something different. Do what they say. Sometimes, this rounded answer is then taken to a later part of the question, so incorrect rounding will affect the rest of the question.

4. On the rare occasions when you're not told, then I stick by 3 decimal places. However, if the answer is a terminating decimal (such as 3.6125 or 0.01234) then write it out in full. Only when you do stuff like a trig question, a square root, stuff with pi, when you get a screen full do you really need to actually round off.

5. Don't be scared to use a fraction when your calculator gives an answer such as 42.66666667. It's 42 2/3!

 

[dolphy-chan]

Okay, that's alot of help! Thanks~! So for percentages should I stick to 3dp?