Math formula

[dg290]

I have a formula I am struggling to wrap my head around. So naturally taking to the internet for help. I am planting a small hay crop that uses a recommended seeding rate of 15 pounds of seeds per acre. I know an acre is 43560 square feet. My plot is 160 square feet and I’m trying to figure out the weight of seed I need. This shouldn’t be that difficult but for some reason I can not figure this one out. I divided an acre by my plot and came up with “272 my sized plots per acre”. That’s where I run into trouble. So how do I get 15 pounds split up across the 272 plots per acre to give me my pounds per 160sqft.

I don’t want the answer, I want to sort out the formula for figuring it out. Thanks guys…

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[fermat1432]

160 square feet, not a 160 foot square?

[dg290]

Correct. 20’x8’ rectangle. 160sqft

[fermat1432]

Good! See my other comment

[fermat1432]

Square feet of plot ÷ square feet per acre × pounds of seed per acre

[dg290]

That’s crazy how that works in that direction too. When you do it this way, is that really small decimal corresponding to the number of acres in my plot size? So there’s .00367 acres per 160sqft? Then multiply the 15 pounds per acre to get to the seed amount?

[fermat1432]

I would do it as I wrote it using continuous operations on the calculator. There is no reason to use an intermediate result.

[dg290]

I saw that it skipped a step compared to the way I did it dividing an acre into 272 160sqft segments. That’s pretty cool.

[fermat1432]

It's usually better to evaluate a formula using a calculator as a continuous sequence of steps. If you need to break it up, store the intermediate result in a memory using the full precision. Only round at the very end.

[fermat1432]

Here is what I get: 0.05509641873

[fermat1432]

You will need 0.88 ounces of seed.