# Problem Solving Puzzles

## Problem-Solving and Number Sense Activities for Teachers and Students

Ever wonder how thick a folded piece of paper can get? Is it possible to calculate the length of the coast of England? Do you think you can use a bicycle to power household appliances? Try your hand at our number games to find your answers. Our number challenges are ideal for playing at home or in the classroom.

• ### All the People in the World

In this activity, estimate how much land is available for each person in the world, based on the world's population.

• ### How Long Is the Coast of England

…How many segments do you need to measure a curved line? This puzzle provides an introduction to the world of fractals.

• ### How Thick Does It Get?

If you fold a piece of paper 50 times, how thick do you think it would be? Try our puzzle to find out.

• ### Number Series

Do you see patterns in a series of numbers? Try our number series and find as many patterns as you can.

• ### Power to the Pedal!

Attach a generator to a bicycle and you can make electricity. But is it enough to actually power a computer? The answer is here.

• ### Square Numbers

Learn all the tricks of square numbers in this series of puzzles.

• ### The Great Soccer Ball Giveaway

How many soccer balls does it take to fill a soccer field? With a little information about the field size and ball diameter, you can figure it out for yourself.

• ### The Reward

Which is more valuable, a set amount of money or an amount that starts small but doubles for each square of the checkerboard? Take a guess before you do the math.