Exploring and noticing

problem

Difference

Age

7 to 11

Challenge level

Place the numbers 1 to 10 in the circles so that each number is the difference between the two numbers just below it.
problem

Marvellous Matrix

Age

7 to 11

Challenge level

Follow the directions for circling numbers in the matrix. Add all the circled numbers together. Note your answer. Try again with a different starting number. What do you notice?
problem

One Million to Seven

Age

7 to 11

Challenge level

Start by putting one million (1 000 000) into the display of your calculator. Can you reduce this to 7 using just the 7 key and add, subtract, multiply, divide and equals as many times as you like?
problem

Triangle Pin-Down

Age

7 to 11

Challenge level

Use the interactivity to investigate what kinds of triangles can be drawn on peg boards with different numbers of pegs.
problem

Sticks and Triangles

Age

7 to 11

Challenge level

Using different numbers of sticks, how many different triangles are you able to make? Can you make any rules about the numbers of sticks that make the most triangles?
problem

More Pebbles

Age

7 to 11

Challenge level

Have a go at this 3D extension to the Pebbles problem.
problem

Polygonals

Age

7 to 11

Challenge level

Polygonal numbers are those that are arranged in shapes as they enlarge. Explore the polygonal numbers drawn here.
problem

Approaching Midnight: Get Started

Age

7 to 14

Like a bit of help getting into the game? Then have a look at this.
problem

Approaching Midnight: What Next?

Age

7 to 14

Want some suggestions about where to go next with the game?
problem

Approaching Midnight: Taking It Further

Age

7 to 14

Here we offer some suggestions about how you could take the Approaching Midnight game further.