Chapter IV – Addition and Subtraction Games with KORBO Blocks
Table of Contents:
- Addition and Subtraction with KORBO Blocks
- Activity 1: “Add and Count”
- Activity 2: “Take One Away”
- Activity 3: “Block Story Problems”
- Activity 4: “Match the Result”
- Activity 5: “Block Math Memory”
- Activity 6: “How Many Blocks Are Missing?”
- Activity 7: “Fill in the Missing Part”
- Activity 8: “Colorful Calculations”
- Activity 9: “Teddy Bear Tasks”
- Activity 10: “Number Train”
Addition and Subtraction with KORBO Blocks
Addition and subtraction are among the first mathematical operations that children encounter in preschool. At this age, it is essential for them to learn numbers and their relationships in a concrete way through manipulation, observation, and play. Thanks to their colors, sizes, and movable elements, KORBO blocks are an ideal educational material for introducing these concepts.
The activities presented in this chapter help children understand that addition means adding elements, while subtraction means taking them away. By working with concrete objects, children learn not only how to count, but also what it means for objects to increase or decrease within a set. The exercises also develop logical thinking, concentration, and the ability to solve simple mathematical problems in everyday situations.
It is worth remembering that learning mathematics at this stage of development is not about memorizing results, but about building number sense and understanding operations. Activities with KORBO blocks encourage children to engage willingly in tasks and gain a sense of success through independent discovery.
Activity 1: “Add and Count”
Educational Objective: Addition Using Concrete Objects
Materials:
A set of Korbo blocks shared by all children (for example, spread out on the floor)
Korbo platforms – three platforms of the same color for each child
Procedure:
Ask each child to connect the platforms in a single line.
Ask each child to take two gear wheels of the same color and place them next to each other in the top row on the left side.
Next, ask them to take two gear wheels in a different color.
Count together, for example: “two blue wheels and two green wheels make four wheels altogether.”
Then ask the children to remove the wheels from the platforms. Repeat the exercise, asking them in subsequent tasks to choose wheels of the same color (but without indicating specific colors yourself).
Note:
Each set contains a limited number of blocks in each color. It is worth encouraging children to choose blocks in colors they select themselves to avoid running out of blocks in a particular color.
Variant:
Pair work – one child chooses the number of blocks, places them on the platform, and counts them aloud.
Activity 2: “Take One Away”
Educational Objective: Subtraction by Removing Elements
Materials:
A set of Korbo blocks shared by all children (for example, spread out on the floor)
Korbo platforms – three platforms of the same color for each child
Number cards from 1 to 6
Procedure:
Ask each child to connect the platforms in a single line.
Ask each child to place six gear wheels in any colors on the platform.
The teacher says: “Take away one wheel.” The child does so and counts how many are left.
Repeat with different instructions: take away 2, 3, etc.
Variants:
Children draw number cards that indicate how many blocks to take away.
Children can carry out the task using cylinders instead of wheels.
Children can build a construction using, for example, 10 blocks (cylinders, connectors, wheels), then remove blocks and count what remains.
Activity 3: “Block Story Problems”
Educational Objective: Addition and Subtraction in a Situational Context
Materials:
KORBO blocks, pictures or illustrations
Procedure:
The teacher tells a simple story:
“There were 4 wheels on the platform.”
(Children take a platform and place 4 gear wheels on it.)
“I added 2 more.”
(Children add two more wheels. The wheels can be stacked to form a tower.)
“How many do I have now?”The children give the answer and justify it: “Four and two make six.”
Variant:
Children invent their own stories and present them to their classmates.
Preparation:
Prepare several simple stories.
Activity 4: “Match the Result”
Educational Objective: Reinforcing Addition and Subtraction Results
Materials:
Cards with operations (for example, 3+2, 5−1)
A set of Korbo blocks shared by all children (for example, spread out on the floor)
Procedure:
The child draws a card with an operation.
The child represents the operation using blocks (for example, 3 red blocks and 2 yellow blocks).
The child counts all the blocks and gives the result.
Variant:
Creating operations for a classmate – one child sets up the operation, the other reads and solves it.
Preparation:
Prepare cards with operations.
Activity 5: “Block Math Memory”
Educational Objective: Linking Operations with Results
Materials:
Cards with operations and separate cards with results
A set of Korbo blocks shared by all children (for example, spread out on the floor)
Procedure:
Lay the cards face down.
Children take one card, read the operation, and calculate it using the blocks.
Then they look for the card with the numeral representing the result of the operation.
They read the operation and the result aloud.
Variant:
Children choose tasks for themselves while working in pairs.
Activity 6: “How Many Blocks Are Missing?”
Educational Objective: Practicing Subtraction in Context
Materials:
A set of Korbo blocks shared by all children (for example, spread out on the floor)
Preparation:
Each child arranges three platforms in a single line.
Procedure:
Ask the children to place 6 blocks next to each other on the platform (these can be gear wheels or cylinders).
The child closes their eyes, and the teacher removes several blocks.
The child says: “I had six blocks, two were taken away, and now I have four.”
Variant:
Children work in pairs and take turns hiding the blocks.
Activity 7: “Fill in the Missing Part”
Educational Objective: Developing Mathematical Intuition
Materials:
Cards with simple equations with a missing part (for example, _ + 2 = 5)
KORBO blocks
A set of Korbo blocks shared by all children (for example, spread out on the floor)
Procedure:
The child arranges the appropriate number of blocks to find the missing number.
The child says the full operation aloud: “three and two make five.”
Variant:
The child creates their own equations for a classmate. For example, they might say: “I have two blocks and I want to have six. How many more do I need to add?”
Preparation:
Prepare cards with simple equations.
Activity 8: “Colorful Calculations”
Educational Objective: Visualizing Numbers
Materials:
Blocks in three colors
Cards with operations
Procedure:
The teacher gives an operation (for example, 2+3).
The children choose 2 blocks of one color and 3 of another color.
They count all the blocks together.
Variant:
The teacher says: “Take three yellow blocks and four green ones. Build a construction with them. How many blocks does your construction consist of?”
(It is worth noting that the connectors are yellow (straight connectors and cross connectors) and gray (cross connectors only).)
If you’d like, I can keep going with the next activity or review the translations for consistency and tone across the whole chapter.
Activity 9: “Teddy Bear Tasks”
Educational Objective: Developing Imagination and Mathematical Thinking
Materials:
A plush teddy bear
KORBO blocks
Cards with instructions
Procedure:
The teacher introduces a teddy bear who “asks” the children to solve tasks, for example: “Build something using 4+2 blocks.”
The child builds a construction.
The teddy bear asks: “How many blocks was this structure built from?”
Variant:
The teddy bear can sometimes “take away” blocks, in which case the task involves subtraction.
Activity 10: “Number Train”
Educational Objective: Adding Consecutive Addends
Materials:
KORBO blocks
A track built from four Korbo platforms arranged in a single line
Procedure:
At the beginning, the children place a number of wheels indicated by the teacher next to each other on the platform (for example, four).
Next, they independently add more gear wheels. They may add one, two, or three.
After adding, they count how many gear wheels they have in total.
The teacher asks:
“We had four gear wheels. How many will we have if someone adds one wheel? So 4+1 = …
Who added two wheels? How many wheels do we have if we added two? So 4+2 = …” and so on.
Variant:
Children build in pairs, adding larger numbers of wheels and counting together in pairs.