Two stones side by side make the stone above them.
Add up the lower stones and write
the result in the stone above.
The filled in numbers show the answer.
Example
What does this exercise practice?
This exercise practices structured adding and builds thinking in connections: how do neighboring numbers relate to each other?
Common pitfalls
Children sometimes start at the top instead of the bottom. Always work from the bottom up! When a stone is missing, you sometimes have to calculate backward, which is harder and may take time.
How to practice at home
Build a little pyramid with blocks or books and let them explain which two lower stones make the upper one. Tangible structures help with understanding.
Related: Number house, Calculation