By: Angela Lenis, Kendra Hutton, Unber Khan, Mitra Malekan, Mary Catherine LaForest, and Stephanie McGee

To teach students how to use the Soroban in order to build number sense, support place value education, and promote multicultural thinking and integrate math with history

● Colourful pony beads● Large popsicle sticks ● Thin wooden sticks that hold the beads● Glue guns ● Dry-erase markers● Overhead sheets to write on with a white

sheet of paper slipped inside

Soroban Goals Curriculum Expectations: Grade 6

Mathematics: Number Sense and Numeration● Quantity Relationships: represent whole

numbers using a variety of tools; demonstrate an understanding of place value in whole numbers and decimal numbers from 0.001 to 1 000 000, using a variety of tools & strategies; read and print in words whole numbers to one hundred thousand, using meaningful contexts

● Operational Sense: use a variety of mental strategies to solve addition and subtraction problems using whole numbers

Materials

Lesson

Introduction (5 minutes)● Ask students, “What do you think people used years ago

to calculate large numbers before we had calculators?” ● Discuss possibilities and then show and let students explore the Soroban.● The teacher then asks the students if they have ever seen or used this before. ● Share a brief history of the Soroban and relate its use to the base-ten blocks (Appendix A).

Lesson (10 minutes)● Introduce the different features (Appendix B).● To ensure students learn how to use the Soroban while staying engaged, present the following:

○ The red beads are called the Heaven Beads: worth 5 units each.○ The white beads are called the Earth Beads: worth 1 unit each. ○ The line in the middle is called the Beam.

● In order for a number to count, the bead(s) must be touching the beam. For example, the Heaven Beads have to come down and touch the beam to count while the Earth Beads have to come up and touch the beam to count. To show the number zero, the Heaven Beads are up in heaven and the Earth Beads are down on earth.

Closure (10 minutes)● Ask students “Why do you think the 1s column (right) only goes up to 9?” ● Together in small groups, begin to represent numbers one by one to ensure that every student

understands the basics. ● Begin by representing one digit numbers moving our way up to 5 digit numbers, as follows: 2, 7, 13,

69, 325, 6479, and 10000.

Possible Extensions

● Break students up into pairs and ask them to develop problems and then solve them ● Addition Races: What’s faster, a Soroban or a calculator?● Show this Youtube video: https://www.youtube.com/watch?v=ADKg9qREdwU and try it yourself!

1

Have you ever wondered how people solved large digit problems before the invention of calculators? Long ago, calculations were done by writing in dust sprinkled on a flat surface, in sand, or by manipulating stones. The Soroban is an Abacus that was introduced to Japan in the mid 16th century. Soroban means a calculating board. The abacus has been used for centuries in Asia and is still an essential part of education to learn arithmetic. It is used not only by children in schools, but also shopkeepers. The abacus is a useful supplement to base-ten blocks for teaching place value. Although number representations on the abacus are not proportional, as they are in base-ten blocks, the rods of the abacus represent places in a base-ten system and the concepts of trading in addition and subtraction still apply. Kambei Mori was a great mathematician who popularized the use of the Soroban in Japan.

Appendix A - History of the Soroban

Appendix B - Instructions for how to build a Soroban

2

Step 1: Take one large popsicle stick and glue five thin wooden sticks to the large popsicle stick. Make sure the thin wooden sticks are evenly spread.

Step 4: Choose twenty colourful “earth” beads of your choice and insert four in each column.

Step 2: Glue another large popsicle stick on top.

Step 3: Take an additional popsicle stick (blue) and glue it on top of one of the red popsicle sticks. This supporting popsicle stick is to make sure the beads can move freely when the Soroban is laying flat.

Step 5: Repeat steps 1 to 3 but this time glue the popsicle sticks ⅓ of the way down. Make sure you glue the supporting popsicle stick on the same side each time.

Step 6: Take an additional five “heaven” beads and insert one bead in each column.

Step 7: Repeat steps 1 to 3 to complete your Soroban.