Coin Puzzle – Triangular Number

I often introduce new puzzles to my kids. I believe puzzles have many important benefits for them. It develops their problem solving skills, and persistence. And it also boost their confidence as they solve it. Today, we tried solving some coin puzzle. Do you know that numbers can also have shapes. For example, the number 10 is a triangular number because you can arrange any ten similar items into the shape of an equilateral triangle. When you do this, the triangle would have four of these items on each side. Can you figure out more triangular numbers ? How about 3,6, 16 ?

For this puzzle, place 10 pennies on a flat surface in the shape of a triangle. Just by moving three pennies, turn it into a triangle that points in the opposite direction.

Still wondering how to solve it ?

Move the rightmost penny in the fourth row to the rightmost column of the second row.

The leftmost penny in the fourth row moves to the leftmost column of the second row.

The one penny in the top row moves to the row in front of the two pennies left in the fourth row.

Voila , your triangle is now facing in the opposite direction. Here are some good puzzle books to have in your book shelves.

( Disclosure : This post contains affiliate links, meaning, at no cost to you, I earn commission if you click through and make a purchase )

Enjoyed doing the coin puzzle, then please consider to follow or like my blog so that you don’t miss out on future posts.

While you are here, check out some more puzzles also

• Pentomino Puzzles
• The Four Four’s Puzzle
• Perimeter Magic Triangle
• LCM – Interesting Smallest Number Puzzle
• 4 x 4 Sudoko on Mother’s Day