Tip:
Highlight text to annotate it
X
Dealing with Significant figures is one of the most confusing things in chemistry, or
science in general. This video will show you how to multiply or
divide using significant figures as well as a shortcut you can take to make your life
easier. Here is a multiple choice question from a
chemistry regents exam asking you to multiply 2 numbers together and then select the answer
that expresses the product to the correct number of significant figures.
Believe it or not, the rules for multiplying and dividing with significant figures are
more basic than for adding and subtracting because you don't need to line up the decimals.
Simply multiply or divide and know that the product or quotient needs to have the same
number of significant figures as the measurement with the fewest number of significant figures.
Now before we do any calculations, we can apply a similar shortcut that we used when
we add or subtract: see how many significant figures each measurement has and then check
which choice has the same number as the fewest! Considering all nonzero digits are significant,
identifying the number of significant figures in all of these measurements was pretty easy.
To find out what to do when zeros get involved, please watch this video for a brief, yet informative
explanation. Now, what if another choice has the correct
number of significant figures that the answer is supposed to have?
In that case, you'll need to continue through with the calculation and round correctly to
arrive at the correct answer. This shortcut works just the same for division
problems. If you picked the correct answer before I
show it to you, just think about how powerful this is if you can answer questions just like
these on your test and get them right in a matter of seconds without even using a calculator!
Give yourself a pat on the back, then decide on what you should do next.
Subscribe to my channel so you can get all of my videos as they come out.
Become a chemvideotutee for free to receive information regarding some of my other products
and services Or, Share this 3 part video playlist covering
everything you need to know about significant figures on twitter, facebook, and linkedin.
Thank you for watching!