Help-- Biology Metric Calculations!

  1. Okay,

    Done with first week of biology and we have a test on Monday on Metric calcuations and conversions. Math is my weekest subject, now I have to learn the Metric system. Ugg! Please suggest websites that will show me step by step examples and give me lots of practice problems.

    Everyone student that has taken this course say's it's soo hard and they barely passed. I am determined to pass this class with an A. I have already started using the CD that came with the text and done practice test for the first 2 chapters but it doesn't show anything for Metric calcuations. I need help now... any suggestions, please.
  2. 1 Comments

  3. by   tfleuter
    if you know how to set up the problem, conversions are easy. here's how i go about it:

    you have 3 quarts of a liquid. how much is that in ml?

    first you need to know how to convert quarts into liters. depending on your teacher, you will either be given the conversion, or you must memorize. in this case, 1 liter = 1.057 quarts. always start off an equation by writing down the information you have been given in the problem:

    (3 quarts)

    next, you will multiply this by the conversion you know. this will be a fraction with the quarts unit on the bottom so that you can cross out both units.

    (3 quarts) (_ 1 liter __) --cross out units--> (3) (_ 1 liter __)
    ________(1.057 quarts) _____________________(1.057)

    now you can't stop here b/c you need your answer in ml. so know you will set up the next "fraction" with liters on bottom and ml on top. since you know tha there are 1000ml in a liter, it will look like this:

    (3) (_ 1 liter __) (1000ml) ----> (3) ( 1 ) (1000ml)
    ____1.057 ______1 liter ________1.057 ___1

    now you will see that the only unit left in the equation is ml which is what we want! now it's time to multiply across top and bottom to see what we get:

    (3)(1)(1000ml) = 3000ml
    (1.057)(1) = ___1.057

    when we divide 3000ml/1.057 we get a final answer of (approx) 2838ml in 3 quarts.

    if you remember to always start with the number/unit given you can usually work out how to get the answer. remember that you are trying to get rid of units "cross multiplication" style which means you can only cross out the unit from the top of one fraction and the bottom of the next. you can't cross out the units if they are both on top or both on bottom. i hope this helps! good luck on your test!

    edited to add: sorry about the additional underlining! for some reason the format won't recognize the extra spaces i have entered inbetween the numbers so they won't line up right w/out the underscoring!