# Spring SAVY 2023: Secrets of the MoLi Stone for Grades 3 & 4

Posted by on Monday, January 30, 2023 in blog, SAVY, Uncategorized.

Day 3: Saturday, February 11

It was wonderful to meet everyone’s families on Saturday! Thank you for taking time to stop by and recognize all the hard work your child accomplished during SAVY!

In the morning we traveled back to China to learn about our final number system! As a class, we concluded that the Chinese system uses groupings of ten and represents place value by using two digits to represent the value and place. Although they share a base and place value with our system, there are more symbols that are difficult to write, including a complex symbol for zero. Learning about this numeration system allowed us to solve the MoLi Stone Mystery! Each week our mathematicians analyzed patterns, groupings, and symbols of multiple number systems to ultimately decipher what the mysterious symbols meant on this stone.

After solving the MoLi Stone, students were given their last task! Creating a new number system was one of the most fun yet challenging activities we did this session.

“What do all numeration systems have in common?”
“Why do we have exactly 10 symbols?”
“How did the Chinese create symbols beyond the symbol for 10?”
“How are the Egyptian symbols related to one another?”

By asking these questions and thinking critically about the parts and rules of each system, students were able to successfully develop their own number system. Many students loved working in base three and decided to create a system in another base. Several students kept with base ten but created symbols that represented things they liked such as baseball, animals, and shapes! What really challenged students’ thinking was that number systems are not just about fun and random symbols for each number but recognizing there was a relationship between the symbol, value, and symbol position. Students beamed with pride as they wrote their symbols on their own MoLi Stone for friends and parents to solve!

In “The Secrets of the MoLi Stone” we studied four different number systems, traveled to three different countries, completed a virtual escape room, and created our own number system! The students loved presenting their hard work. I encourage you to have them present to other friends and family who could not make it this weekend!

1. What is the name of your number system? How did you come up with this idea?
2. What patterns can be seen in your system?
3. How are numbers grouped in your system?
4. Explain the symbols in your system.
5. Try to figure out your students MoLi Stone using the information on their poster!

It was wonderful to meet so many bright young scholars! Teaching a child is a team effort, and it is because of you and your dedication to their education that they are so successful! I hope to see everyone in another SAVY session this summer!

Day 2: Saturday, February 4

Session two had students traveling all over the world as we continued to analyze the patterns, groupings, and symbols of different numeration systems. Our first stop was the Land of Treble! In the Land of Treble, everything is in groups of threes. From the tires on cars, to the toes on people’s feet, to the petals on flowers, and even a base-three numeration system, you will find everything in a triad.

The students LOVED exploring this mysterious land. Not only is the numeration system in base three, but there are silly names to go with each value. A group of one is called a gickle, a group of three is called a bickle, a group of nine is called a rickle, and a group of twenty-seven is called a trickle! Kids loved saying these names throughout the day! Students were given a series of challenges they had to complete to travel back home. Each challenge had students experimenting and exploring the base three system more in depth. Level one had them adding gickles, bickles, and rickles in order to make a trickle! Just as we group by sets of ten in a base-ten system, other bases are grouped and traded in a similar way. Students learned to group and trade for another value in base three, and that the only digits in base three are 0,1, and 2.

To pass level two, our mathematicians practiced subtracting in base three with the goal of having zero gickles on their boards. It was important for students to see that the grouping and renaming process is the same whether adding or subtracting, in base three or base ten. Finally, level three had students using both addition and subtraction. Once each pair completed these activities, the entire class had to compare and contrast the base three and base ten system. They were very engaged as we tried to figure out the base three code for each of our numbers in base ten. For example, 27 in base ten would be equivalent to 1-0-0-0 (one, zero, zero, zero) in base three.

In the afternoon students ended up in Egypt. Just as they were given a series of challenges to complete in order to escape the Land of Treble, they were given a similar series of tasks in Egypt. We began by learning about the meaning of symbols and how we use them to represent numbers. Students needed to figure out the value of the seven different Egyptian symbols through analyzing a set of numbers with the corresponding Egyptian symbols. They learned how to read and write Egyptian numerals and then add and subtract quantities using these symbols. All these activities lead them to think about the characteristics of our base-ten system and compare our numeration system to the Egyptian system.

Students were fascinated with how many symbols it takes to write a four-digit number! Did you know it takes 25 Egyptian symbols to write 5,749 takes 25? This is because numbers were created by repeating symbols of similar value so that the total number of symbols summed to a quantity of adding the digits together. Our mathematicians also discovered there is no zero in the Egyptian number system or a symbol for anything larger than one million!

The ideas discussed in session two were very sophisticated. We concluded the day by taking the conclusions about the base three, Egyptian, and base ten systems and connecting them to our generalizations for systems.

Day 1: Saturday, January 28

What a great start to our spring SAVY session! I was blown away by the enthusiasm and excitement from our group of students! All of them came with a willingness to try new things, and it was fun to hear about their talents and passions as we introduced ourselves.

In the morning we got to know one another while studying archaeology. Students created their own “secret rooms” with artifacts and hieroglyphics to describe themselves. During the next two Saturdays, students will have the opportunity to uncover “secrets” about one another and share their rooms. Next, we discussed the concept of systems in depth. A system is a group of related parts that move or work together. I was so impressed with how the students could sort between what a system is and is not after introducing this concept. I think several of them were blown away by how many systems were all around us!

We continued our journey of uncovering the MoLi Stone by looking at the patterns, groupings, and symbols within our own base ten system. We played three games that helped explain place value verses face value, regrouping and renaming numbers, and understanding the importance of place value in addition and subtraction.

The Meneki Neko Bank was our first challenge. It challenged students to find how many ways to make 47 cents using dimes and pennies. Students loved hearing about Meneki Neko cat and the legends behind this Japanese good luck charm. Next, students were introduced to Card Capers. In this activity, students worked in pairs to create the largest two-digit number. While this may seem simple, students could only draw one card at a time, and had to choose where to place the card before drawing the next one (ones place, tens place, or discard pile). After each team played several rounds, they created “cheat sheets” with the strategies they used to create the largest number.

Finally, students played Some Sum and Some Difference using their “cheat sheets” from Card Capers. This game continued to deepen students’ place value knowledge as they created the smallest and largest sum and difference while only drawing one card at a time and placing it down before drawing the next card! By the end of our session, students were one step closer to solving the mysterious symbols on the MoLi Stone. I cannot wait to continue our journey next week as we focus on number systems with different bases!