Chayei Sarah - Unit Conversion

"And it was, when the camels had finished drinking, the man took a golden nose ring, its weight a beka, and two bracelets on her arms, ten gold shekels their weight." ~Bereishit 24;22

Unit Conversion:

Unit (or Unit of Measure): a standard amount of a physical quantity (ref. dictionary.com)

In Math and Science, units are a critical aspect of calculation. Units, in simple terms, are the base quantity that we choose to use to measure physical properties- a length, a weight, a volume, etc. You can measure with standard units- units that are already established by society and have specific value assigned to them (e.g inch, cm, pound, gram, gallon, liter, etc.); You can also measure with non-standard units- units that you choose for you convenience, but are not standardized to all places and situations (e.g. the paperclips that I have in a box on my desk, or the length of my right foot).

In order to compare measurements of different items, we need to measure them using the same units. This is where unit conversion comes in. If we have items measured in different units, then we need to convert them all to the same units of measure in order to be able to say how they compare to each other. We need to know how many cm are in an inch, and then make sure that all items we're comparing are measured in either cm or inches. In general, it doesn't matter which measure you choose to use, you just need to pick one and make sure that everything that you're comparing is measured with the same measure. If I want to compare my height over the past 5 years, I can measure myself consistently in ft, or I can have some measurements in ft and some in meters, but in order to compare, I need to convert all the measures to either ft or meters to know how my height has changed. Note that in order to calculate the conversion from ft to meters or vice versa, I need to know that 1 meter is approximately 3.28 ft.

So, how does this connect to the parsha?

In Chayei Sarah (Bereishit 24), Avraham's servant, Eliezer, is sent to find a wife for Yitzchak. When Rivkah meets him at the well in Nahor and she offers water to both him and his camels, he realizes that she is the right woman for Yitzchak. He then, in Bereishit 24:22, gives a gift to her-- and here is where we find units of measure. Eliezer gives her "...a golden nose ring, its weight a beka, and two bracelets on her arms, ten gold shekels their weight."

So, what if we want to know how much the weight of her jewelry was altogether? Or, how big was the nose ring compared to the bracelets? How can we compare the weight of a beka and the weight of ten shekels? Rashi helps us out here and tells us that a beka is the weight of a half-shekel (see Rashi on this Pasuk to see how he knows this). So, we now we know that the nose ring was the weight of a half-shekel and the two bracelets were the weight of 10 shekels. So, the weight of all of Rivkah's jewelry from Eliezer was 10.5 shekels. The weight of the two bracelets together was 20 times the weight of the nose ring. Or, if we assume that the bracelets were equal in weight, then each bracelet was 10 times the weight of the nose ring.