Second Grade Humanities: Stratigraphy Sandwiches

Today in second grade humanities we discussed stratigraphy.  We talked about how looking at the layers of the Earth is really important to archaeologists.  We learned that the oldest layer is on the bottom and the newest layer is on the top.  To demonstrate the concept, we built our own Stratigraphy Sandwiches.

Here are the supplies, just waiting for the kids to arrive:

The first thing the students did was set one piece of bread on their plate.  The bread represented a field in Virginia.

Next, I told the kids that a flood (the field was near a river) had occurred, causing a layer of mud to settle over the the field.  The kids spread a layer of chocolate frosting on the bread to represent the mud.



A group of Archaic people came to camp at the site.  They left a circle of rocks from their fire pit and some charcoal from their fire.  The students placed a circle of chocolate chips on the site to represent the rocks, and sprinkled sprinkles in the middle to represent the charcoal.


After a time, the Archaic people moved on, and a layer of dirt and rock covered the site.  To represent the layer of dirt, the students placed another slice of bread on top of their “sandwich.”

Later, another group, this time the Powhatan, came to the site.  They built shelters.  The students used their knives to dig holes in the top slice of bread to represent the post holes the Powhatan dug in the Earth.


The Powhatan made pottery, some of which was broken or destroyed.  The Powhatan dug holes and threw the broken pottery in the holes.  To represent this, the students dug more holes in their bread and buried pieces of “pottery” (M&M’s) in the holes.


The Powhatan moved on.  The proximity of the site to the river resulted in another flood.  To represent the flood, the students spread a layer of blue frosting on top of their bread.  For many of the kids, this resulted in some redistribution of the “pottery.”  We talked about how this can happen at a real site, and how archaeologists need to account for this type of movement when they excavate and analyze artifacts.

Through time, I told the kids, other layers of dirt accumulated, until the present and final layer of dirt covered the site.  To represent this final layer, the kids placed one last piece of bread on top of their sandwich.

This led us to present day, when an archeologist, suspecting that the field was a prehistoric habitation site, conducts random samples and surveys.  The kids took samples of their own, randomly poking a straw through the three layers of the sandwich to see what they could find.  When they came across a sprinkle, a chocolate chip, or an M&M, they knew that they had found an area that could have been a habitation site.


The archaelogist decides to conduct a test excavation at the site.  To represent this, the kids cut a small square out of their sandwich and examined the stratigraphy of the square.  It was easy to tell the layers apart.  We talked about how it’s not always so easy in real life.


I asked the students what would happen if I put their sandwiches in a blender.  Would they be able to examine the layers then?  Could they tell which items were found where?  They agreed that it would then be impossible to tell.  We compared that to when a habitation site is bulldozed or looted.

What would happen to the sandwiches if we separated them, layer by layer, to excavate the contents within?  They certainly wouldn’t be sandwiches anymore.  This is true at excavation sites in real life — archaeology is a destructive process.  Procedures at a dig are precise because once a site is excavated, it is destroyed.  There are no second chances.

After all that working and talking, it was time to eat our stratigraphy sandwiches.  If you thought the kids would hesitate to dig in to a three-layer frosting sandwich, you thought wrong.


All in all, we learned a lot and may have had a bit of fun along the way.  A successful endeavor, if you ask me.


Second Grade Math: Roman Numerals and the Super Bowl

I just finished discussing Roman numerals with my kindergarten math students, and today here I was talking about them again with second grade math groups as part of our Can You Count in Greek? unit.  Many of the second graders remembered learning about Roman numerals in kindergarten.  Most of them needed a refresher course, especially when it came to subtractive notation.  We went over all of the basics and then they got down to work.

In most classes, we also talked a bit about the Super Bowl.  After all, I started doing Roman numerals at this time of year because it’s always interesting for the kids to look at the different Super Bowl logos and figure out what the Roman numerals stand for.  This year, for the first time, we couldn’t do that.  That’s because this year’s Super Bowl logo looked like this:

in contrast to last year’s, which looked like this:

In 2014, the NFL announced that they wouldn’t be using Roman numerals as part of the logo for Super Bowl 50:

Super Bowl

Why do you think the NFL made this decision?  Explanations vary, from design elements (L is an asymmetrical letter mostly made of negative space) to negative connotations the letter L brings (L is associated with losing and losers).  You can read more about it here and here.

Wishing everyone a relaxing and fun long weekend!


Second Grade Enrichment Math: Ancient Greek Numbers

This week in second grade enrichment math, we talked about Ancient Greek numbers (and how they were extra confusing because the characters were the same for both letters and numbers).  The kids practiced writing numbers using the Ancient Greek characters.  Like the Ancient Egyptian system of numeration, this is an additive number system with no place value.  While the students worked, there were many cries of “what do I put when there’s supposed to be a zero?!” intermixed with “this is sooooooooooo haaaaaaard!!”

The kids engaged in a little healthy competition to see who could correctly complete the most problems the fastest.  In the end, the leaders for each group were Jacob; Mason; Nicholas, Zoe, Corinne and Sylvia (a four-way tie); and Zoe K.  Everyone worked really hard and they will be ready to move on to a new number system next week… will we finally find a system with place value?


First Grade Enrichment Math — Setting a Price

This week in first grade enrichment math, we continued working to help the Rosada family while they work to open their restaurant, La Tostada Sabrosa.  The students have been helping the Rosadas figure out how many three-ingredient tostada combinations were possible (ten), and they did such a good job that the Rosadas returned for more assistance!

The Rosadas provided the students with a list of their ingredient costs.  The students then needed to find out how much each of the ten tostada combinations would cost to make.  They spent their class time diligently adding up ingredient costs.  Once they determined the cost for all ten combinations, they listed the costs in order from least to greatest.

The Rosadas question is:  if they want to charge one standard price for all of the tostada combinations, what should they charge?  Some of the students reached the point where they were ready to discuss what the price should be, but most of them didn’t.  We will be ready to talk about this next week.  I’ll also be talking to the kids about mean, median, mode, and average, and we’ll calculate each of these and use the information to help us when we set a price.

The homework asked the kids to complete a similar task — figure out the least and most expensive sandwich combinations at a sandwich shop and pick a standard price to charge for all sandwiches.  I hope it was simple and straightforward!

First Grade Reading — You Think You’ve Got Problems?

The first grade enrichment readers are busily working on their inventions unit.  They’ve been trying to generate problems that inventions could solve.  For some, this has proven somewhat difficult.  (More than a few students actually lamented “But I don’t haaaaaave any problems!”  It was difficult to muster too  much sympathy.).

To give them a little nudge, I presented the kids with several problem scenarios:

  1. The merry-go-round on a local neighborhood’s playground has been removed. Too many children have been injured while playing on the equipment. Your task is to design a safe merry-go-round to keep children from getting hurt.
  2. I have a long, steep driveway that slants toward the street.  I have to carry the garbage can to the end of the driveway each week for trash pickup. The can is big and heavy and it’s both impossible for me to lift and  difficult for me to drag through the gravel driveway. Your task is to invent something to make this job easier.
  3. One of your chores is to feed your cat.  You don’t like the way the cat food smells or feels, and you especially don’t like washing the spoon when you are finished.  How can you solve this problem?

The kids talked about the problems and tried to come up with solutions.  The first problem was the most difficult, though there were many inventive solutions, like trampoline walls and seat belts.  The second problem was the easiest, and in every group someone came up with the idea of adding wheels to the trash can.  The third problem gave rise to lots of creative ideas.  The students were impressed to learn that the problem was drawn from the real life of Suzanna Goodin, who invented the Edible Pet Food Spoon as a solution when she was in the first grade.

To wrap up our session, the students worked to identify problems they could solve with a simple invention they can make at home.  They brought home a graphic organizer to help them generate more ideas.  They don’t need to fill out the entire thing, but they should have at least two solid ideas.  The kids will be creating inventions of their own, but not for a few weeks now.  More information to follow!

Kindergarten Reading — Palindromes

This  week, we read Mom and Dad are Palindromes by Mark Shulman and Adam McCauley.

The book is about a boy named Bob who discovers that his life is made up of tons of palindromes.  He finally decides to stop the madness by going by his full name — Robert Trebor.  (Not such a helpful strategy, it turns out).  We talked about how palindromes are words (or phrases or numbers) that read the same forwards and backwards.  We counted the palindromes in the book and came up with some of our own.  WOW, was it fun!

This week’s homework is a spread from the book featuring Bob’s teacher, Miss Sim.  The kids need to fill in the background of the picture with palindromes — either words or phrases.  This shouldn’t be too taxing, so no one should worry about getting “too hot to hoot.”

Kindergarten Math — I Value Xylophones Like Cows Do Milk

How ’bout that title?  Did your child come home saying that crazy sentence?  (If not, please say it yourself and see how your child reacts!)  Can your kindergarten student tell you what that sentence means/what the letters stand for?

I wrote the sentence on the board at the start of class and read it to the kids.  I wrote each of the capital letters in red ink and the rest of the letters in black.  The kids were easily able to figure out that the red letters were important for some reason, but they were stumped as to why.  Gradually, we made our way to the conclusion that the letters are the Roman Numerals.  We then wrote down the letters and their values:

  • I = one
  • V = five
  • X = ten
  • L = fifty
  • C = one hundred
  • D = five hundred
  • M = one thousand

We talked about how to write and read Roman numerals.  We didn’t watch Brain Pop in class, but if your student needs a refresher, Brain Pop has a great movie about Roman numerals (here).  Most of your children should be familiar with Brain Pop (and Brain Pop Jr.) from school.  The mini-movies on the site are chock full of great information. You need a login to access them — our login name is tjelem and the password is tiger.  This only works during school hours (or so I’m told).

Subtractive notation isn’t easy.  We practiced finding numbers where a lower number was written to the left of a higher one, and reminded ourselves that the numbers need to be read as a pair and the one on the left needs to be subtracted from the one on the right (ex. IV = 4).  This is probably the easiest way to do the homework — group the numbers that require subtractive notation and circle them, then subtract and add as necessary.  This is how we did it in class, so it should look familiar to the kids.

The homework is a single-sided sheet of problems — writing Hindu-Arabic numerals as Roman numerals and vice versa.  It is difficult!  Please help your child work to/through frustration, but if s/he reaches the breaking point (or you do), pause or skip.

I hope you know that I understand that this stuff is not typical kindergarten fare.  From the homework coming back, it seems like you do — the kids are taking their best shot at things and leaving off when they reach frustration level.  That’s what they should be doing.  I don’t expect all of the kids to get these higher-level concepts all of the time.  A lot of it may go over your child’s head.  That’s okay!  Exposure is important, and while they may not remember (or understand) all of what we talk about, they’ll each take away their own pieces of information.

Keep valuing those xylophones!