## Step 6: Measure

Place two large intelligent looking books under the binder to allow your scale some room to move.

Trays like this measure unknown weight against a known weight. Most of us don't own 1, 5, or 10 gram masses. But we all have coins. And US coins have a weight tolerance to about a hundredth of a gram. Which is more than we need for this project.

US pennies are 3.1 grams, those printed after 1982 are 2.50 grams.
Quarter weighs 5.67 grams
Dime 2.27 grams
nickel 5.00 grams

Now I don't know if the mass of the other coins are date dependent, like the penny. Because of this I prefer to use pennies.

From here I'm sure you can figure out the rest, measure out your rocket fuel and mediate on your MacGyver skill. Have fun!

(I don't know why this photo is slanted, it's really a feature)
How much does each paper tray weigh?
oh, and you can find coin weights in wikipedia! (At least for euros)
That's almost like my idea! I managed to measure weights in 10mg accuracy. I use a transparent ruler and I simply balance it on a triangular ruler (http://www.woodrow.net/oneProduct.asp?productId=38). I simply put the coin on the ruler (the ruler on my construction is horizontal) on one side and the thing I want to weigh on the other, suspended on a thin string from the edge of the office. I measured the accuracy by using the scale to measure the weight of some coins with other coins. I'll sometime make an instructable for mine too, the good thing about mine is that it doesn't use tape(exept for the cointainer of the item to be measured). Well done for your scale too! I wanted to see if someone else thought about it and posted it.
&nbsp;at least there's a formula for this
I like the part about coin weights! Very informative.
Cool idea! The only problem with using packaged food for the known weight is that that should be the weight of the food not including the packaging. If You were to use the ketchup bottle then your weight would be off considerably if it was a glass bottle. It would probably work using a dry good dumped into your matching weight trays though. I'm sure this will come in handy some day!