The building is made of identical cubes, and every stack stands on the floor.
Count stack by stack and write the total number of cubes in the box.
For bigger buildings it pays to count each row on its own first and then add the rows together.
Example
For parents
What does this exercise practice?
Counting in space practices organizing a set instead of guessing it, and leads from counting to adding up equal rows.
Common pitfalls
The stacks at the back are half hidden. Their top face still shows how high they are, and below it the stack continues down to the floor.
How to practice at home
Build something from rows of equal height and work it out instead of counting, three rows of four cubes are 3 times 4.