Spatial thinking trainer

Count the corners: how many do all the shapes have?

Also known as: how many corners do the shapes have, count the angles, how many vertices does a polygon have

You see two, three or four shapes. Count the corners of each one, add them up and pick the total from four options. Gradually the shapes become irregular, and concave ones appear. You can play 10 minutes a day without signing up.

Go to the game ↓

1.5 minutesper round
4 levelsfrom two shapes to four
No sign-up10 minutes a day
Progress30-day chart

What it trains

Why count corners

You need to make out each shape quickly, keep count and add up the results. Regular shapes are recognized at a glance, but irregular and concave ones have to be counted corner by corner.

You lose count when counting objectsCounting by eye
You mix up similar shapesA pentagon and a hexagon differ by one corner
You want a numbers task without equationsThe numbers come from the picture
Your child is learning geometric shapesFamiliar shapes in a game

Visual perception

Recognize the shape quickly.

Counting

Add up the corners of the shapes in your head.

Attention

Don’t skip a corner or count one twice.

Decision speed

The faster you answer, the more tasks you get per round.

Rules

How to play

Start
Press “Start”. Polygons and four answer options appear.
Count
Count the corners of each shape. Corners that point inward count too.
Answer
Tap the total number of corners. On a computer, pick an option with keys 1–4.
Level
Three correct answers in a row move you up a level: there are more shapes, and they become irregular and concave. A mistake drops your level.
Score
A correct answer earns as many points as your current level, and a mistake costs one. After a minute and a half you’ll see your result.

Play online

Count the Corners online

Count the corners of all the shapes and pick the total. Play 10 minutes a day with no sign-up.

Count the Corners

A few polygons appear on the screen. Count their corners in total and pick the answer. The number of shapes grows, and irregular ones appear.

Free play left today without signing up: 10 min

Method

What the exercise is based on

A polygon has as many corners as it has vertices. At the first levels the shapes are regular and recognized as a whole; further on they are irregular, and you have to count every corner.

If you want more counting, try Quick Math. And Shape Rotation adds working with shapes in your mind.

2Two shapesRegular shapes from a triangle to a pentagon

3Three shapesUp to seven corners, irregular shapes

4Four shapesUp to eight corners, some concave

Who it’s for

Which ages

Adults

A minute and a half of attention and counting, no equations.

Kids

Suitable from age 6 if your child can count to 20: for kids there are no more than three regular shapes on the board.

60+

A calm pace: there’s no time limit per answer, just one timer for the whole round.

Questions

Frequently asked questions

Do corners that point inward count?

Yes. In a concave shape every corner counts, both outer and inner.

Why are the answer options so close?

They differ by one to three corners, so you can’t guess by estimating; you have to count.

Can I play with a keyboard?

Yes: keys 1–4 pick an option from left to right.

Do I need to sign up?

No, you can play 10 minutes a day right away. A free account lets you keep playing, save your results, track your progress and unlock the daily workout.

Does it work on a phone?

Yes, the trainer runs in the browser on phones, tablets and computers. Nothing to install.

Save your results and track your progress

Free sign-up: round history, a chart by skill and a daily workout of 5 exercises. No credit card needed.

All trainers

Count the corners: how many do all the shapes have?