Physics CH 0: General Introduction (4 of 20) How to Determine Significant Figures in Operations

In this video I will determine the significant number to the final answer when adding, subtracting, multiplying, dividing, and squaring numbers.

Next video in the series can be seen at:

[coveringjapan]

6.20x10^2

Thank you Professor van Biezen. These videos are helping me so much in my Physics class.

[iloverobot]

Thank you for these lectures! I am homeschooled so this is my physics class I have chosen to take and study by myself.. It’s so very helpful with getting started and feels like I’m back in a real classroom ^_^

[fenny]

At 7:05, the division problem should be 6.20 x 10^2 right? The value is 620. so it should be two decimal places to the left.

[abdullasahib]

Isn't the rule for square roots (exponent of 1/2) that you take the number of decimal places under the radical and apply it to the final answer? So, you would get only one significant figure for the final answer, since the original number (48.6) only had one decimal place

[richardcrilley]

If you read my comment on ambiguous numbers the multiplication problem you did with 56 as a multiplier would require an answer without a decimal point. When you put that decimal point in that answer, you are implying you know more about the significant figures than you actually do. That is why you have numbers without decimals (or you should). Here is a rough example. if I wanted a stick as a measuring tool to be 56 inches long and I chopped one off of a branch with a hatchet what I thought was 56 inches. Then I use that stick, with its ambiguous measure to multiply 24.3 times. I can't put a decimal point in that answer, it wipes out the ambiguity. Now if it is a situation where I am chopping the stick to about 24.3 inches and I multiply it 56 times (without a decimal point) the 56 is a counting number and the significance is infinite. That is not an ambiguous case. Like I said before, we have situations in math where we need a way to express an ambiguous multiplier or multiplicand and numbers without decimal points is the best way to do that.

[vuhung]

I'm a bit confused at the first problem. Since 4.5 has only 2 SF, therefore the answer should be 17, isn't it? Because 17.0 has 3 SF

[schadrackmuhawenayo]

First, I thank you for your lessons, if possible teach how can combined and expanded uncertainty of spiked sample are calculated.

[haleyshaw]

I have a question on the 4th example. Why is the answer 6.20x10^3 and not 6.20x10^7 since the answer is 619.5402299? Why do we just for get the last 4 numbers? Same goes for the 5th example, why not write it as 6.97x10^7? Do we drop the rest of the significant figures if they are less than 5?

[dianchristina]

hello i think the answer in problem #4 must be 620. (with a point) because it must be 3 significant figure but 620 is only 2 sig fig while when there is a point it will become 3 sig fig.

[umairshah]

I am preparing for my tests in university
These lectures are great Sir
I am from Pakistan

[alihusseintalib]

shouldn't the last problem be 6.97 x 10^2 ?

[johnvalgon]

when we should use SF
at any problem or in certain ones like they must have decimal ?