Showing posts with label shekel. Show all posts
Showing posts with label shekel. Show all posts

Thursday, June 18, 2015

Korach- Currency Equivalency Activities

"Every first issue of the womb of any flesh that they offer to Hashem, whether of man or of animal, shall be yours; but you shall surely redeem the firstborn of man, and the firstborn of an impure animal shall you redeem. And those that are to be redeemed- from one month shall you redeem according to the valuation, five silver shekalim by the sacred shekel; it is twenty geirah." ~Bamidbar 18:15-16
Towards the end of this week's parsha,  we read of what items are set aside to be given to Aaron and the Kohanim. Within this section, we learn that firstborn male infants and firstborn animals are part of what is to be given to the Kohanim. However, we also learn that firstborn children and impure firstborn animals are to be redeemed at the age of one month. The value for redeeming them is 5 silver shekalim, and we are told that one silver shekel is equivalent to 20 geirah.

Activity Suggestions related to Monetary Equivalence:
Learning equivalencies of monetary values can be confusing for young children. Opportunities for hands-on acting out with manipulatives, repetition, and practice help them become proficient in working with monetary conversions.

  • Students can convert between geirahs and shekalim.                        
    Given that 1 shekel = 20 geirah:
    • Representing the conversion-
      • Younger students could calculate how many geirahs would be in 5 shekalim, by using manipulatives for representation. They could have cups to represent 1 shekel, and small chips or counters representing a geirah. Students could work together to create shekel value cups, each filled with 20 geirah. Once they have the cups set up, they can then go back and count out 5 shekalim. 5 cups would represent 5 shekalim. 
      • Students who are ready could draw representative circles or boxes for shekalim and show 20 tally marks within each one to represent the geirahs in each. In this case, 5 circles or boxes would represent the 5 shekalim. 
    • Making the calculations-
      • Youngest students can work together (or as a class) to count out how many geirahs there are all together in the 5 shekalim. 
      • Slightly older children could use their knowledge of "skip counting" or addition of simple large numbers to add the twenties together and make the calculation.
      • Older students can use their knowledge of multiplication to problem solve and calculate how many geirahs would be in 5 shekalim.
  • Follow-up calculations:
    • Can students (young and old) figure out how many shekalim would be needed to redeem multiple firstborns? If 7 families redeem their firstborns, how many shekalim would be given to the Kohanim all together? How many geirahs would be given to the Kohanim all together?
    • If you chart the redemption values in shekalim and geirahs for different numbers of firstborns, can you identify any patterns?
    • For upper elementary or middle schoolers- can they convert the patterns that they find into functions? How would these functions look when graphed?
  • Older students can also research conversion values to current day currencies. Based on the researched conversion rates, what is the value today of a geirah? of a shekel? How much would families need to pay to redeem firstborns in different countries today? Can they write a function to calculate redemption values for multiple firstborns using current currencies?

Thursday, May 21, 2015

Bamidbar- Reading, Comparing, and Calculating with large numbers

Note that the section of quotes from this week's parsha is quite long in order to show the context for Levite and firstborn census numbers. As always, I organize all of the information for you beginning below the quotes. If your time is short, feel free to scroll past the citations.
"Hashem spoke to Moshe in the Wilderness of Sinai, saying, 'Count the sons of Levi according to their fathers' house, according to their families, every male from one month of age and up shall you count them.' Moshe counted them according to the word of Hashem, as he had been commanded.
These were the sons of Levi, by their names: Gershon, Kohath, and Merari. These were the names of the sons of Gershon according to their families: Livni and Shimei. The sons of Kohath according to their families: Amram and Izhar, Hevron and Uzziel. The sons of Merari according to their families: Mahli and Mushi. These are the families of the Levites, according to their fathers' house.
For Gershon- the Livnite family and the Shimeite family; these are the Gershonite families- their counted ones according to the number of every male, from one month of age and up: their counted ones [were] seven thousand, five hundred." ~Bamidbar 3:14-22
"And for Kohath- the Amramite family, the Izharite family, the Hevronite family, and the Uzzielite family; these were the Kohathite families- the number of every male from one month of age and up [was] eight thousand, six hundred; the guardians of the charge of the sanctity." ~Bamidbar 3:27-28
"For Merari- the Mahlite family and the Mushite family; these were the Merarite families- their counted ones according to the number of every male from one month of age and up [was] six thousand, two hundred." ~Bamidbar 3:33-34
"All the counted ones of the Levites, which Moshe and Aaron counted by the word of Hashem according to their families, every male from one month of age and up, were twenty-two thousand.
Hashem said to Moshe, 'Count every firstborn male of the Children of Israel from one month of age and up, and take a census of their names. You shall take the Levites for Me- I am Hashem- in place of every firstborn of the Children of Israel, and the animals of the Levites in place of every firstborn of the animals of the Children of Israel.' Moshe counted- as Hashem had commanded him- every firstborn of the Children of Israel. Every firstborn male according to the number of their names, from one month of age and up, according to their countings, was twenty-two thousand, two hundred and seventy-three.
Hashem spoke to Moshe, saying, 'Take the Levites in place of every firstborn of the Children of Israel, and the animals of the Levites in place of their animals, and the Levites shall be Mine, I am Hashem. And as for those redeemed of [the firstborn], the two hundred and seventy-three of the firstborn of the Children of Israel who are in excess over the Levites, you shall take five shekels each according to the head count, in the sacred shekel shall you take; the shekel is twenty geirah. You shall give the money to Aaron and his sons, of those redeemed in excess among them.'" ~Bamidbar 3:39-48
In this week's parsha, we learn of multiple censuses that were taken in the desert. Last year, I looked at the census information for the 12 Israelite tribes. This census was taken for men from the age of 20 years old and older. In my post last year, I analyzed that information from a basic statistical averages viewpoint- exploring the mean, median, and mode for the data set of the census. 

This year, I would like to look at the census information for the Levites. Since we're dealing with a lot of information here, let's first focus and pull out the numerical information that we're trying to look at. The census information for the Levites is first broken down into smaller census numbers from the individual Levite families, and then summed up at the end. Then, following that information, there is another census of the firstborn Israelites. We will look at all of these sets of information.

Let's begin by weeding through the information above to organize the pertinent information that we need:
Gershon- 7,500 males from 1 month of age and older
Kohath- 8,600 males from 1 month of age and older
Merari- 6,200 males from 1 month of age and older

Then, the total sum listed for all Levites is 22,000 males from 1 month of age and older

Stop for a minute and test out this calculation. 

  • Does 7,500 + 8,600 + 6,200 = 22,000? In fact, it actually adds to 22,300. 
So what's going on here? Why does the Torah omit 300 Levites in it's calculation? Rashi on 3:39 deals with this exact question. He explains that the total number of Levites was needed in order to redeem the firstborn Israelites. For every 1 Levite, 1 firstborn Israelite would be redeemed. Rashi says that the 300 Levites who are not included in the total sum were actually firstborns, themselves, and therefore would not count towards being able to redeem other Israelite firstborns, since they would be redeeming themselves.

Let's look on further- We are told that the firstborn Israelite males from 1 month of age and older totaled 22,273. 

So, if we replace one-for-one each firstborn Israelite with a non-firstborn Levite, we have 22,273 firstborns & 22,000 Levites available for redeeming:
22,273 - 22,000 = 273

Now, it seems that we have 273 firstborns who do not have a Levite to redeem them. If we continue reading, though, we see that Hashem has told Moshe that there are, in fact, 273 firstborns "in excess" of the Levites, and these 273 should be redeemed by collecting 5 shekels per person for each of them and that money will go to the Kohanim. 

Some other thoughts & activities:
  • It my be interesting to compare the census for the Levites with the census of the rest of the Israelites that's listed in the first part of the parsha. In making a comparison of the numbers, it would be important to keep in mind that the census for the 12 Israelite tribes was taken from 20 years and older, while the Levite census was taken from 1 month and older. Even more so, what interesting findings do you see when comparing the numbers of the two groups?
  • An interesting discussion topic may be to think about whether there is a way to compare the information given for the general Israelite census to the firstborn Israelite census to figure out any further information regarding numbers of Israelites between certain ages? Is there enough information given to create comparisons of smaller age groups- either from each tribe or from the whole group?
  • For younger students, it might be interesting to just think about place value and reading large numbers. Students could have a matching activity in which they have to identify the numbers of the censuses and match them to the appropriate tribes. Students could also talk about how to think about comparing which numbers are larger and which numbers are smaller- place values and how you can use place values to compare numbers to each other to figure out which is larger and which is smaller. Students who catch on quickly to this concept could think about ordering the numbers from smallest to largest or largest to smallest.
  • Follow-up activity- values are given for how many shekels were collected for the 273 "excess" firstborns who did not have Levite redeemers (Bamidbar 3:50). Older students could check the calculations for the values to see if it matches the amount that they calculate should have been donated. We are also told (Bamidbar 3:47) that a shekel was worth 20 geirah. Students can calculate a conversion of the value to also figure out the value of the donation in geirahs. 

Thursday, May 14, 2015

Behar/Bechukotai- Graphs, Patterns, and Calculation Activities

"Hashem spoke to Moshe, saying: Speak to the Children of Israel and say to them: When a man will express a vow to Hashem regarding the valuation of souls, the valuation of a male shall be: for someone twenty years of age to sixty years of age, the valuation shall be fifty silver shekels, of the sacred shekel. If she is female, the valuation shall be thirty shekels. And if from five years of age to twenty years of age, the valuation of a male shall be twenty shekels and of a female ten shekels. And if from one month of age to five years of age, the valuation of a male shall be five silver shekels; and for a female, the valuation shall be three silver shekels. And if from sixty years of age and up, if for a male, the valuation shall be fifteen shekels; and for a female, ten shekels. But if he is destitute for the valuation, then he should have him stand before the Kohen, and the Kohen should set his valuation; according to what the hand of the person who makes the vow can attain should the Kohen set his evaluation." ~Vayikra 27:1-8

In this section of this week's parsha, we learn about the standard valuation for donations that are vowed to the Beit HaMikdash on behalf of family members. We have the standard valuations, and we are also told that if someone makes a vow but doesn't have the funds to meet the standard valuations, the Kohen can make a determination of an appropriate valuation for that person. This week I would like to look at some activities for students of varying levels based on the standard valuations that are listed.

To begin, let's organize the information (older students could be asked to chart this information for themselves by identifying and organizing the information in the passage):


Note that this could also be organized into two charts- one for males and one for females. This breakdown might be clearer for some students when trying to separate information on males and females in follow-up activities.

Related Activity Suggestions:

  • Graph It!- A good way to compare data of this nature is by graphing it. This information lends itself well to a double bar graph, with a category for each age grouping, and two bars within each category (one for males and one for females). The left side of the bar graph (y-axis) would indicate the number of shekels donated. As always, grade levels recommended are an approximation, and individualization for students is necessary to meet their actual ability levels. K-2 students could fill in a pre-made class-sized graphing chart as a class activity, with older students also copying the information onto personal graphs. Grades 3-5 students could create individual graphs on pre-printed graph templates with spacing indicated for different levels of labeling, and then graphing the information. Students in grades 6+ could create their own double-bar graph from start to finish.

  • Is there a pattern?- Looking at the table above and/or the double-bar graph created in the first activity, students can look for comparisons between males and females at each age group. They can also look for comparisons between the different age groups for males and then between the different age groups for females. 
    • What trends do they see over a person's lifetime? Is this consistent for both men and women? Why do they think the valuations may have been set in the way that they were?
    • After making note of comparisons, older students could look for specific numerical comparisons between males and females in each age group and then across the data for males and females at different age groups. Are any of the ratios between groups consistent in any way? Rashi's note on 27:7 is also relevant to these comparisons, as he specifically points out some differences in the ways that the valuations change between the different age groups.
  • Problem Solving- Processing the information through sample family valuations- Using the valuations given, students could be provided with sample problems with different family groupings to calculate the valuation for each family. Students could also create their own sample families to calculate or switch with friends to calculate. What about students' own families? What would each student's personal family valuation be if they were donating to the Beit HaMikdash? Can older students come up with an algebraic formula for calculating the valuation for any given family scenario?

Thursday, November 13, 2014

Chayei Sarah- Currency related activity ideas

A note to readers- Having written a full cycle of parsha posts, I've decided to try a slightly different approach. For this next cycle, I'm beginning with identifying a concept and then posing concept specific questions and activities for investigating the concepts at varying academic levels- still K-8 level.  I'd love feedback from readers as I keep the process going. Are you just an interested reader? Am I still keeping you interested? Are you a teacher/parent looking for ideas? Which ideas do you find most helpful? Have you tested out any ideas with your students/children? Looking forward to your feedback!
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"...And Ephron replied to Abraham, saying to him: 'My lord, hear me! Land worth four hundred silver shekalim; between me and you- what is it? And bury your dead.' Avraham listened to Ephron, and Avraham weighed out to Ephron the money that he had mentioned in the hearing of the children of Heth, four hundred silver shekalim in negotiable currency. And Ephron's field, that was in Machpelah, that was facing Mamre stood- the field and the cave within it and all the trees in the field, within its entire boundary all around- as Avraham's as a purchase in the view of the children of Heth, with all who came to the gate of his city. And after that, Avraham buried Sarah his wife in the cave of the field of Machpelah facing Mamre, which is Hevron, in the land of Canaan." ~Bereishit 23;14-19

Activity Connections:
The two ideas that stand out to me from this passage are:
1) Avraham's weighing out of the money
2) The fact that the Torah specifically says that he was using "negotiable currency"

For some previous thoughts about scales and balance, see my post on Parshat Ki Teitzei where I talk about weights and measures.

Rashi on 23;16 explains that "negotiable currency" is stated because the shekel that the Torah usually refers to is a smaller shekel (equal to 1 sela). In our case, though, Avraham chose to use shekels which are acceptable as currency even in areas that use larger shekels ("kanterin", which are equal to 100 selas). 

Activity ideas in increasing conceptual difficulty:
*Discussion and exposure to local current-day currency; discussion around equivalent currencies
eg. for US currency, exposure to pennies, nickels, dimes, quarters, half-dollars, dollar coins, dollar bills, etc and discussion/practice with the value of each and equivalencies (5 pennies = 1 nickel; 25 pennies = 1 quarter = 5 nickels = 2 dimes + 1 nickel)

*Combine currency with the idea that Avraham weighed out his money. Does this still work with current day currency? Will 5 pennies balance with 1 nickel on a balance scale? Our current money is more of a representation of value than true equivalence between coin sizes, weights, and values.

*Look at the difference between what 400 shekalim would have been if they were each 1 sela instead of being 1 kanterin. This can be done at varying levels for different ages and abilities. What does it physically look like using manipulatives to represent 1 sela? How could you calculate how many selas Avraham actually paid Ephron? 

*If you look at the comments section in last year's post on Chayei Sarah, you'll find a link to some calculations on current day equivalence for a shekel (one that's the value of a sela). How can you use this information to calculate the current day value for what Avraham actually paid for Maarat HaMachpelah? How different is that from what he would have paid in current day currency if he used selas instead of kanterin?

*How does the amount of money paid toward Maarat HaMachpelah compare to the value of Rivkah's dowry (the bracelets and nosering discussed in last year's post)? How does a beka compare to a sela? to kanterin?

*If you compare the difference between values of selas and kanterin, is the difference linear growth or exponential growth? (Hint: 1 kanterin = 100 selas; 2 kanterin = 200 selas; and so on)

Thursday, February 27, 2014

Pikudei- Mixed Measures

"All the gold that was used for the work- for all the labor of the Sanctuary- the offered-up gold was twenty-nine kikar and seven hundred thirty shekel, in the shekel of the Sanctuary. The silver of the accountings of the assembly, a hundred kikar, one thousand seven hundred seventy-five shekel, in the shekel of the Sanctuary." ~Shemot 38;24-25

"The offered-up copper was seventy kikar and two thousand four hundred shekel." ~Shemot 38;29

Rashi on 38;24 explains that a kikar of the Sanctuary is three thousand shekalim, and, therefore, the individual shekalim that are listed are mentioned because together they don't add up to one kikar.

What is a "mixed measure"?:
Understanding how to measure with standard measurements is a basic skill that students begin practicing with from an early age. How many feet long is the room? How many cups of water are in the pitcher? But, what happens when you don't have enough to complete an exact measurement with the measure that you're using? What if the room is between 10 and 11 feet long? What if the pitcher has between 5 and 6 cups of water? Sometimes we use fractions to indicate these middle measures. However, we also have other, smaller measurements that can be used to measure these partial portions. We have a standard equivalency that 12 inches are equivalent to 1 foot, for example. So, if my room is between 10 and 11 feet long, I can measure the "extra" length using inches. Maybe my room is 10 feet and 3 inches. This type of measurement is known as a mixed measure. To simplify a measurement out of a mixed measure, we could convert the mixed measure into the larger measurement using a mixed number (a whole number with a fraction) or decimal, or we could convert the mixed measure into the smaller measurement. With our room example, 10 ft 3 in would be 10 1/4 ft or 10.25 ft when measured only in feet, or 123 inches when measured only in inches. For younger students, the calculation for converting the mixed measure into the smaller unit (from feet and inches to just inches) is an easier one and also helps to give them a better sense of the full meaning of the number, where mixed measures and mixed numbers are often harder for them to visualize and fully understand.

Let's calculate:
So how do we convert to the smaller measure unit? Let's use our 10 ft 3 in room example. We know that 1 foot is made up of 12 inches. So, we multiply 10 x 12 (10 feet, with 12 inches in each) = 120 inches. Then, we add the extra 3 inches that were left over, so 120 + 3 = 123 inches.

What does this have to do with the parsha?:
In this week's parsha, Rashi helps us understand that the weight measurements that we're given for the gold, silver, and copper that were donated to the mishkan are mixed measures using kikar and shekalim. Rashi explains that 1 kikar = 3,000 shekalim.

The amounts that we are given in the parsha are:
Gold: 29 kikar and 730 shekel
Silver: 100 kikar and 1,775 shekel
Copper: 70 kikar and 2,400 shekel

How can we convert these to all shekalim measures?
We know that 1 kikar has 3,000 shekalim, so:
Gold: 29 x 3,000 (29 kikar, with 3,000 shekalim in each) = 87,000 + 730 shekel = 87,730 shekel
Silver: 100 x 3,000 (100 kikar, with 3,000 shekalim in each) = 300,000 + 1,775 shekel = 301,775 shekel
Copper: 70 x 3,000 (70 kikar, with 3,000 shekalim in each) = 210,000 + 2,400 shekel = 212,400 shekel

So, our final calculations after converting from mixed measures to just shekalim are:
Gold: 87,730 shekel
Silver: 301,775 shekel
Copper: 212,400 shekel

A further thought:
The silver calculation is particularly meaningful, since we are told "a beka for every head, a half-shekel in the shekel of the Sanctuary for everyone who passed the counters, from twenty years of age and up, for the six hundred three thousand, five hundred fifty." (28;26) So, our silver calculation should be accurate for 603,550 men 20 years of age and older having each given a 1/2 shekel. Does this work? 
301,775 shekel of silver x 2 (two 1/2-shekel pieces for each shekel) = 603,550 1/2-shekel pieces.
So, it seems that there isn't even estimation here, but rather the calculations work exactly!

Thursday, October 24, 2013

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.