Think of two numbers
Elevenses
Partly painted cube
Your number was...
Reversals
Your number is...
Multiplication arithmagons
Can you find the values at the vertices when you know the values on the edges of these multiplication arithmagons?
Arithmagons
Can you find the values at the vertices when you know the values on the edges?
More number pyramids
When number pyramids have a sequence on the bottom layer, some interesting patterns emerge...
What numbers can we make?
Imagine we have four bags containing a large number of 1s, 4s, 7s and 10s. What numbers can we make?
Summing consecutive numbers
15 = 7 + 8 and 10 = 1 + 2 + 3 + 4. Can you say which numbers can be expressed as the sum of two or more consecutive integers?
Pair products
Choose four consecutive whole numbers. Multiply the first and last numbers together. Multiply the middle pair together. What do you notice?
What numbers can we make now?
Imagine we have four bags containing numbers from a sequence. What numbers can we make now?
Number pyramids
Try entering different sets of numbers in the number pyramids. How does the total at the top change?
Special numbers
My two digit number is special because adding the sum of its digits to the product of its digits gives me my original number. What could my number be?
What's it worth?
There are lots of different methods to find out what the shapes are worth - how many can you find?
How old am I?
In 15 years' time my age will be the square of my age 15 years ago. Can you work out my age, and when I had other special birthdays?
The Number Jumbler
The Number Jumbler can always work out your chosen symbol. Can you work out how?
Fruity totals
In this interactivity each fruit has a hidden value. Can you deduce what each one is worth?
Treasure hunt
Can you find a reliable strategy for choosing coordinates that will locate the treasure in the minimum number of guesses?
A little light thinking
Here is a machine with four coloured lights. Can you make two lights switch on at once? Three lights? All four lights?
What's possible?
Many numbers can be expressed as the difference of two perfect squares. What do you notice about the numbers you CANNOT make?
Pick's theorem
Polygons drawn on square dotty paper have dots on their perimeter (p) and often internal (i) ones as well. Find a relationship between p, i and the area of the polygons.
Shifting times tables
Can you find a way to identify times tables after they have been shifted up or down?
Charlie's delightful machine
Here is a machine with four coloured lights. Can you develop a strategy to work out the rules controlling each light?