Chapter V

Multiplication and Division

Why is it worth teaching multiplication and division through action?

The skill of multiplying and dividing is one of the milestones in a child's mathematics education. It makes it possible not only to calculate more efficiently, but also to solve word problems, analyze data, think logically, and plan actions in everyday life.

For children at the early-school stage, multiplication can cause quite a lot of difficulty. It already requires somewhat abstract thinking, which is not easy for them to visualize, especially with higher numerical values.

Division is something that is a natural activity for children. From the earliest years they learn it by watching cutting, sharing, and sorting. It would seem that these skills would make carrying out numerical division operations the easiest mathematical challenge to master. Meanwhile, in the world of mathematics they encounter difficulties caused by transferring these skills to abstract mathematical operations carried out on numbers alone.

Pupils aged 7–9 learn best through activity, play, handling materials, and observation. That is why in this chapter we use blocks — a tool that fits these needs perfectly. Children can physically arrange groups, share them out, build repeating patterns, observe relationships, and draw conclusions.

Thanks to different types of blocks — gears, cylinders, platforms, and connectors — children not only understand the structure of mathematical operations, but also engage in the learning process on many levels: motor, visual, auditory, and verbal.

After completing the work in this chapter, the pupil:

  • Understands multiplication as repeated addition, e.g. 3 × 2 is three times two.
  • Understands division as sharing a whole into equal parts or groups.
  • Builds models of multiplication and division operations using blocks.
  • Carries out simple multiplication and division operations mentally or with the help of concrete objects.
  • Records operations using mathematical symbols: ×, ÷, =.
  • Solves simple word problems that use multiplication or division.
  • Compares the results of operations, analyzing which are greater/smaller.
  • Uses inverse operations (multiplication–division) and notices the relationship between them.
  • Completes missing elements in an operation (e.g. _ × 3 = 12; 16 ÷ _ = 4).
  • Uses division with a remainder and can show it with concrete objects.
1

Introduction to Multiplication

Learning goal

Understanding the idea of multiplication.

Needed elements

  • Blocks
  • Worksheets with operations

How it goes

The teacher builds three identical towers, each from two gears. The teacher asks a pupil to say how many towers there are, and then to write the number on the board. The teacher asks another pupil to count how many gears are in one tower and write it on the board. The teacher says that there are three identical towers, in each tower there are two gears, and asks the pupils how many gears there are in all the towers. The teacher writes the operation 3 × 2 = 6. The teacher explains to the pupils what the multiplication sign means.

The teacher gives one more example (e.g. 4 × 3 = 12), stressing that the towers are the same.

The teacher divides the children into groups; each pair gets a set of blocks and worksheets with operations to solve. The children build towers and solve the tasks.

2

Multiplication Activities on Platforms

Learning goal

Consolidating multiplication through addition.

Needed elements

Blocks

How it goes

The teacher builds an 8×8 mat from platforms. Then the teacher places three gears in the first row and asks a pupil how many gears there are on the mat, writes the operation on the board (three gears in a row 1 × 3 = 3), then takes the gears off and places four gears in the first row and four gears in the second row, saying: we have four gears in the first row and we will add a second row with the same number of gears, that is two rows of four gears, 2 × 4 = 8. The teacher shows two more examples (e.g. 5 × 4 = 20 and 8 × 3 = 24).

The teacher divides the children into teams of four; each team gets worksheets. The children build an 8×8 mat and number the rows and columns. The children solve the tasks by placing the matching numbers of gears in rows and columns on the mat, according to the written operation.

3

Swapping Towers

Learning goal

Understanding the commutative property of factors in multiplication.

Needed elements

Blocks

How it goes

The teacher builds three towers consisting of two gears, the first tower from red gears, the second from blue gears, the third from yellow gears. The teacher asks the children how many towers there are, how many gears in each tower, and how we will write the equation. A child writes the equation on the board (3 × 2 = 6). Then the teacher rebuilds the towers so that two identical towers of three gears are created; each gear in a tower is a different color. The teacher shows the towers to the children and asks them to check whether the number of gears in both towers has not changed. The teacher explains that from three towers two were built, but from the same gears, so 2 × 3 = 6. The teacher gives two more simple examples explaining the commutative property of factors in multiplication.

The teacher divides the children into pairs; each pair gets a set of blocks and worksheets with operations to solve. The children build and rebuild towers and solve the tasks.

4

Swapping Columns and Rows

Learning goal

Understanding the commutative property of factors in multiplication.

Needed elements

Blocks

How it goes

The teacher builds an 8×8 mat, places five gears in the first, second, and third row on the mat, asks a child to count the gears and write the operation (3 × 5 = 15). Then the teacher takes the gears off and arranges them five at a time in the first, second, and third column, asks a child to count the gears and write the operation (5 × 3 = 15).

The teacher divides the children into teams of four; each team gets two sets of blocks and worksheets. The children build an 8×8 mat and number the rows and columns. The children solve the tasks by placing the matching numbers of gears in rows and columns on the mat, according to the written operation.

5

Colorful Multiplication

Learning goal

Practicing multiplication with colorful gears assigned values.

Needed elements

Blocks

How it goes

The teacher places graphics of four gears on the board, each in a different color. To each gear the teacher assigns a given numerical value, e.g.:
● red gear = 3
● blue gear = 5
● purple gear = 6
● yellow gear = 7

Then the teacher asks a pupil to draw one gear; the teacher draws a second gear and hands it to the pupil for the other hand; the pupil writes on the board the values matching both gears and the result of the multiplication.

The teacher divides the children into pairs; each pair gets several gears in different colors. Children take turns drawing gears, similarly to the pupil–teacher setup (one child takes one gear, the other chooses theirs and hands it to the first); the first pupil calculates the result and gives it to the second, who checks whether it is correct.

6

Encoded Shapes

Learning goal

Understanding the idea of division.

Needed elements

Blocks

How it goes

The teacher builds a tower from eight gears. The teacher shows it to the children and writes 8 on the board, then divides the tower into two equal parts of four gears each and asks the children into how many towers the large tower was divided and how many gears both towers have, writes the equation 8 ÷ 2 = 4 on the board. The teacher explains the “÷” sign to the children. Then the teacher puts the tower of eight gears together again, but this time divides it into four towers of two gears each. The teacher asks the children to count the towers and say how many gears each of them consists of, and writes the equation 8 ÷ 4 = 2.

The teacher divides the children into pairs. The teacher says a number of pieces that the children are to take together from the container and a number of groups that the children are to arrange (in each group there is to be the same number of blocks).

Variants

The children sit back to back and at the same time carry out instructions proposed by the teacher, e.g.:
● build a tower from 6 gears and divide it into 3 equal parts; how many gears will there be in each part?
● build a tower from 12 gears and divide it into 4 equal parts; how many gears will there be in each part?
● build a tower from 4 cylinders and divide it into 2 equal parts; how many cylinders will there be in each part?
● build a tower from 9 gears and divide it into 3 equal parts; how many gears will there be in each part?

7

Division with a Remainder

Learning goal

Explaining the idea of a remainder in division operations.

Needed elements

Blocks

How it goes

The teacher points to a box in which there are 22 cylinders and asks three pupils to share them among themselves. The pupils conclude that they are not able to share the blocks equally among themselves. The teacher writes the operation 22 ÷ 3 and explains to the children what division with a remainder means. Then the teacher asks one pupil to add as many cylinders to 22 as needed so that they can be shared equally among three people, and to write the equation.

The teacher divides the children into pairs; each pair gets a worksheet with division. Using cylinders, the children solve the equations and record the results of operations with and without a remainder.

8

What Is the Divisor

Learning goal

Practice in division.

Needed elements

Cylinders

How it goes

In pairs, children receive worksheets with equations in which the divisor is replaced by a graphic of a colorful gear. Helping themselves with cylinders, the children are to assign the correct value of the divisor to the color of the gear in the graphic. The teacher explains that the divisor is another way of saying into how many groups the total number of all the blocks should be divided.

9

The Commutative Property of Multiplication and Division

Learning goal

Understanding the relationship between multiplication and division.

Needed elements

Blocks

How it goes

The teacher has a prepared tower of twelve gears, places it on a platform, and writes the equation 12 ÷ 4 = 3 on the board (asks a pupil to give the result). The teacher divides the tower of gears into four parts, then asks a pupil to say how many towers they see and how many gears they consist of. The teacher writes the equation 4 × 3 on the board, then asks a pupil to say how many gears there are altogether, and writes 12. In the same way, the teacher presents the operations 15 ÷ 5 = 3, 5 × 3 = 15, and so on, and explains to the pupils that the result of division can be checked through multiplication.

10

Division by Building Groups (Dividing by 4)

Learning goal

Division as creating equal groups.

Needed elements

  • Gears
  • A platform

How it goes

The pupil receives 12 gears and is to share them equally onto 4 pegs of the platforms. Conclusion: 12 ÷ 4 = 3.

Variants

Change the number of groups.
“Inexact” division — e.g. 13 ÷ 4 and discussion of the remainder.

11

Team Split

Learning goal

Division through assigning pieces.

Needed elements

  • 12 cylinders
  • Cards with the number of children in a group

How it goes

The pupil has 12 “team members” (cylinders). They divide them into, e.g., 3 teams — 4 people each. Then 4 teams — 3 people each.

Variants

Pupils check how many members a team has in different team sports (e.g. soccer, volleyball, basketball, futsal, rugby, and so on), choose as many blocks as there are members of the team, and check whether these teams can be divided into several groups.

12

Gear Multiplying Machine

Learning goal

Strengthening automatic recall of multiplication facts.

Needed elements

  • Gears
  • A platform as a machine (5 platforms arranged next to one another)

How it goes

Work in pairs / groups. The group chooses a number (e.g. 5), builds a “machine” from 5 gears turning in a row. Then onto each gear they place 3 more: 5 × 3 = 15. They count the number of blocks.

Variants

A team game: who will “produce” faster the result of the operation indicated by the teacher.

13

Building According to an Operation

Learning goal

Creating mathematical models.

Needed elements

Blocks

How it goes

The pupil draws a card with an operation (e.g. 6 ÷ 2). They are to build a construction from 6 pieces and divide it equally into 2 parts.

Variants

Add a spoken description — “The construction has 6 parts, each group has—”.
Arranging operations for their own buildings.

14

The Game “Who Has More”

Learning goal

Comparing the results of multiplication and division operations.

Needed elements

  • Sets of blocks
  • Cards with operations

How it goes

In pairs, children draw operations, carry them out with blocks, and compare the result — who has more?

15

Block Equations

Learning goal

Completing missing data in an operation.

Needed elements

  • Gears
  • Cards, e.g. _ × 4 = 16

How it goes

The pupil tries through building to find the missing value — e.g. they arrange 4 blocks in groups until they reach 16.

Variants

Completing division: 24 ÷ _ = 6.
A team game — guess what is missing. A group shows the operation on a card and what they have built. Another group's task is to discover what is missing (e.g. a whole tower, or gears in the towers), e.g. the group has the operation 5 × 4 = 20 and from the blocks five towers of three blocks were built.