Math Cheat Sheet

Discussion in 'Landscape Architecture and Design' started by Guido, May 25, 2001.

  1. Guido

    Guido LawnSite Silver Member
    Messages: 2,087

    I think when I get some spare time this looooong weekend, I'm going to make a math cheat sheet for new guys ( and some old ) in the business since a lot of people usually have trouble with this. I'll e-mail it out and put it on my website too.

    Do you guys have any ideas of what all I should include? I'll do the conversion stuff and Cu. Yds., apshalt and concrete, Weights of used products, inches to feet chart, and some other stuff. Let me know if you guys have any other ideas.
  2. Guido

    Guido LawnSite Silver Member
    Messages: 2,087

    Let me know if its missing something. I just threw it together quickly for now. I'll improve it after sugeestions and put it somewhere on my home page.

    Guido Asked that I remove the old document.
    paul, moderator
  3. eskals

    eskals LawnSite Member
    Messages: 210


    Looks like a good start.

    On this line: Area of a circle = Pi(3.14) x Radius x Radius

    I would just say 3.14 x radius x radius

    The way it is written now, it could be interpreted as 3.14 x 3.14

    Also, might not be a bad idea to include somewhere on the sheet that when making calculations, you must always have the same units. EG. You can't multiply inches and feet and get something meaningful.

  4. stslawncare

    stslawncare LawnSite Bronze Member
    from DE
    Messages: 1,484

    very good start, may also want to incorporate a soil chart, mulch chart, etc etc. the more of the math that u do, the more resourceful it will be, i have found a decent soil chart, but im still looking for that perfect paper or papers that do all the math for me for all the different materiales of all the sizes weights etc etc etc
  5. Dennis

    Dennis LawnSite Member
    from Ga.
    Messages: 155


    9sq ft = 1 cu yd ?? Am I missing something?
    Also could you include how to work with bags of Mat. from Garden store, by using Examples. As in 100 Sq ft of mulch using 2 cu ft bags,I work better seeing examples,bad in math.
  6. paul

    paul Lawnsite Addict
    Messages: 1,625

    Why do you need one for soil and one for mulch, both are Cu. Yd measures?
  7. Stonehenge

    Stonehenge LawnSite Bronze Member
    from Midwest
    Messages: 1,276

    Here are a few thoughts -

    Always specify units when giving formulas. When you have a formula for volume, specify the units, so someone doesn't multiply inches and feet. Do that on every formula.

    And you can't divide yards by 1.3 and get meters. There are 100 centimeters in a meter. There are 2.54 cm in an inch. Therefore, there are 39.37 inches in a meter. This is 1.094 the length of a yard. So, multiply yards by 1.094 and you get meters.
  8. Ron Persaud

    Ron Persaud LawnSite Member
    from Florida
    Messages: 17

    I find it useful to write all the measurements in the same units from the very first time. If I have to mulch a strip 100 yards long by 3 feet wide to a depth of 3 inches, I might decide to calculate in feet.
    The measurements now become 300ft by 3ft by 3/12ft.
    cu.ft. = 300 x 3 x 3 (2700)and divide the answer by 12. (225)
    If a bag has 2 cu.ft. then estimate for 113 bags.
    If you need the answer in cu.yd. then divide the cu.ft. by 27.
    If you play around with some simple things it is amazing how not-so-simple they are. Calculate the volume of a cardboard box and then take it apart carefully. Now calculate the area of cardboard it took to make the box.

    And quickly now, which has more fenceline? A square or oblong piece of property with the same square footage?:)
  9. Guido

    Guido LawnSite Silver Member
    Messages: 2,087

    Okay, Just got back from my mini-vacation to Amsterdam, so I'm still a little hazy, but when I wake up, I'll fix my typo's on that sheet and try to organize it better.

    Thanks for the feedback guys, let me know if there is anything else you would like to see.
  10. Guido

    Guido LawnSite Silver Member
    Messages: 2,087

    Okay, I fixed a few typos I had, changed all the conversions from metric to standard and standard to metric. Added a chart for inch to decimal conversions. If you downloaded the first one, please download this one to replace the file you d/loaded earlier in the thread.

    ESKALS - Yeah, I thought the circle one was confusing the way I wrote it, should have just kept it simple, I changed it now though. Again, I should have kept it simple and said to make sure to keep all of the units the same, noted that in the revised one too. Thanks for the help!

    STS LAWNCARE (SCOTTIE) - Those are all Cu. Yd. Measures. They are all pretty much the same. The only variation I've seen is to add .05% when ordering concrete to make sure you have enough in case of voids in your base course or for crete that slips under your forms, etc.

    DENNIS - Your right, it was a typo! Sorry about that! As far as your request, you can just figure out the area and then divide by how many bags. For example if you have to do a 100 Cu. Ft. Area and your bags spread 5 Cu. Ft., than you would need 20 bags of material.

    PAUL - Thank you Paul, as always!

    STONEHENGE - Okay, not sure what happened but we were both wrong, I think. I think I have it down right this time though, check it out and let me know. Thanks!

    RON - Your right, we can make anything complicated! It does get crazy after you think about it too long, thats why I'm trying to make it easier for some that don't feel comfortable doing the math.

    Now, for your trick wuestion, its the same amount of fence, right? ;)

    Okay Guys, let me know if you see anything else you want fixed or added.

    Thanks Guys!

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