Myriora Non-verbal Reasoning › 11+ non-verbal reasoning › Chapter 3: Think in 3D

Counting cubes

11+Chapter 3 · Lesson 3

In this lesson

Every cube sits on the ground, or on another cube.
Count one column at a time.
Count down to the ground.
Add the columns together.

Your turn

How many cubes are in this stack?

Show the answer

The answer is eight! Three, two, two and one make eight.

The common mistake

Here's a common mistake. Counting only the cubes you can see. The tall column has cubes that are hidden behind the others. They still count.

Try it at home

Build a stack with sugar cubes or building blocks. Count it column by column, then take it apart to check.

Read the whole lesson

Hello, and welcome to Myriora Non-verbal Reasoning! How many cubes are in this stack? You can't see all of them, so you need a way to count.

Here's the way. Every cube sits on the ground, or on another cube. So count one column at a time. Look at the top of the column, and count down to the ground.

Let's count this stack. The tall column has three cubes. The next has one. The next has two. And the last has one. Three, one, two and one make seven.

Let's try one together. How many cubes are in this stack? Here's a tip: count one column at a time. Say it out loud!

The answer is five! Two, one, one and one make five.

Here's a common mistake. Counting only the cubes you can see. The tall column has cubes that are hidden behind the others. They still count.

Your turn! How many cubes are in this stack? Pick the right card. You've got ten seconds, or pause the video. Go!

Time's up! The answer is eight! Three, two, two and one make eight.

Quick review. Every cube sits on the ground, or on another cube. Count one column at a time. Count down to the ground. Add the columns together. See you next time!