Chapter IV
Addition and Subtraction Games with Blocks
Addition and subtraction with blocks
Addition and subtraction are among the first mathematical operations children meet in preschool. At this age it is essential that they get to know numbers and their relations in a concrete way - through handling objects, observation, and play. Blocks, thanks to their colors, sizes, and moving parts, are an ideal teaching material for introducing these ideas.
The games in this chapter help children understand that addition is joining objects and subtraction is taking them away. By working with concrete materials, the child not only learns to count, but also understands what it means for objects to be added to or taken from a set. The activities 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. Games with blocks make children eager to take part in the activities and give them a sense of success through their own discoveries.
Join and Count
Learning goal
Addition with concrete objects.
Needed elements
- A set of blocks for all the children to use together (e.g. poured onto the carpet).
- Platforms - three of the same color for each child.
How it goes
1. Ask each child to join the platforms in one line.
2. Ask each child to take two gears of the same color and place them next to each other in the top row on the left-hand side.
3. Then ask them to take two gears of a different color.
4. Count together, e.g. "two blue gears and two green gears make four gears altogether".
5. Then ask the children to knock the gears off the platforms. Repeat the activity, asking them in later tasks to take gears of the same color (but we no longer name specific colors).
Note: Each set has a limited number of blocks in a given color. It is worth asking the children to choose blocks in colors they pick themselves, so there is no shortage of blocks of a particular color.
Variants
Work in pairs - one child chooses the number of blocks, places the blocks on the platform, and counts.
Take One Away
Learning goal
Subtraction by removing objects.
Needed elements
- A set of blocks for all the children to use together (e.g. poured onto the carpet)
- Platforms - three of the same color for each child.
- Cards with digits 1-6
How it goes
- Ask each child to join the platforms in one line.
- Ask each child to place six gears of any colors on the platform.
- The teacher says: "Take one gear away". The child does this and counts how many are left.
- Repeat with different instructions: take away 2, 3...
Variants
- Children draw cards with numbers showing how many to take away.
- Children may do the task with cylinders instead of gears.
- Children may build a construction from e.g. 10 blocks (cylinders, connectors, gears) and subtract blocks from it, then count.
Block Story Problems
Learning goal
Addition and subtraction in a situational context.
Needed elements
Blocks, pictures or illustrations.
How it goes
- The teacher tells a simple story: "There were 4 gears on the platform. (Children take a platform and place 4 gears on it). I added 2 (Children add two more gears - they can place gears on gears - as a tower). How many do I have now?"
- Children give the result and explain: "Four and two make six".
Variants
- Children invent their own stories and ask them of their classmates.
- Prepare several stories.
Match the Result
Learning goal
Consolidating addition and subtraction results.
Needed elements
Cards with operations (e.g. 3+2, 5?1),
a set of blocks for all the children to use together (e.g. poured onto the carpet).
How it goes
The child draws a card with an operation. They arrange a representation of that operation from blocks (e.g. 3 red and 2 yellow). They count them all and give the result.
Variants
- Creating operations for a classmate - one arranges, the other reads the operation.
- Prepare cards with operations.
Block Math Memory
Learning goal
Linking operations with results.
Needed elements
Cards with operations and separate cards with results
A set of blocks for all the children to use together (e.g. poured onto the carpet).
How it goes
Spread the cards face down. Children take one card each, read the task, and count it out with blocks. Then they look for the card with the digit that is the result of the operation. They read the operation and the result out loud.
Variants
- Children choose tasks for themselves in pairs.
How Many Blocks Are Missing
Learning goal
Subtraction practice with a context.
Needed elements
A set of blocks for all the children to use together (e.g. poured onto the carpet).
How it goes
Preparation: each child arranges three platforms in one line.
Ask the children to place 6 blocks on the platform side by side (these may be gears or cylinders). The child closes their eyes, and the teacher takes a few blocks away. The child says: "I had six blocks, two have been taken away and I have four left".
Variants
- Children work in pairs and take turns hiding the blocks.
Fill in the Gap
Learning goal
Developing mathematical intuition.
Needed elements
Sheets with simple equations with a blank space (e.g. _ + 2 = 5), blocks,
a set of blocks for all the children to use together (e.g. poured onto the carpet).
How it goes
The child arranges the right number of blocks to find the missing number.
They say the whole operation: "three and two make five".
Variants
The child creates their own equations for a classmate. They may, for example, say: "I have two blocks, and I want to have six. So how many more do I still need to take?"
Colorful Operations
Learning goal
Visualizing numbers.
Needed elements
Blocks in three colors, sheets with operations.
How it goes
The teacher gives an operation (e.g. 2+3), the children choose 2 blocks of one color and 3 of another. They count them all together.
Variants
- The teacher says: "Take three yellow blocks and four green ones". Build a construction from them. How many blocks is your construction made of? (it is worth noting that the connectors are yellow (straight connectors and cross connectors) and gray (cross connectors only).
Teddy Bear Tasks
Learning goal
Developing imagination and mathematical thinking.
Needed elements
A teddy bear, blocks, slips with instructions.
How it goes
- The teacher introduces a teddy bear who "gives" the children operations: "Build something from 4+2 blocks".
- The child builds a construction.
- The teddy bear asks: how many blocks was this building made from?
Variants
- The teddy bear may sometimes "take away" blocks - then the task is subtraction.
The Number Train
Learning goal
Adding successive parts.
Needed elements
Blocks, a track built from four platforms placed in one line.
How it goes
- To start, children place on the platform, side by side, the number of gears given by the teacher (e.g. four).
- Then they add more gears on their own - they may add one, two, or three.
- After adding, they count how many gears they have.
- The teacher asks - We had four gears. How many will we have if someone added one gear? So 4+1 =.... Who added two gears? How many gears do we have if we added two gears? So 4+2 is .... and so on.
Variants
Children build in pairs, adding larger numbers of gears, and count together in pairs.