How much peel does an apple have?

How is the length of time between the birth of an animal and the birth of its great great ... great grandparent distributed?

Take any pair of numbers, say 9 and 14. Take the larger number, fourteen, and count up in 14s. Then divide each of those values by the 9, and look at the remainders.

Take ten sticks in heaps any way you like. Make a new heap using one from each of the heaps. By repeating that process could the arrangement 7 - 1 - 1 - 1 ever turn up, except by starting with it?

Learn how to use logic tests to create interactive resources using Excel.

Use an Excel spreadsheet to approximate a decimal using trial and improvement.

This investigation uses Excel to optimise a characteristic of interest.

Learn how to use the Excel functions LCM and GCD.

Learn how to use lookup functions to create exciting interactive Excel spreadsheets.

Choose four numbers and make two fractions. Use an Excel spreadsheet to investigate their properties. Can you generalise?

This spreadsheet highlights multiples of numbers up to 20 in Pascal's triangle. What patterns can you see?

Learn how to use conditional formatting to create attractive interactive spreadsheets in Excel.

Learn how to use composite bar charts in Excel.

Use Excel to create some number pyramids. How are the numbers in the base line related to each other? Investigate using the spreadsheet.

Use Excel to investigate remainders and divisors. Was your result predictable?

Learn how to use Excel to create triangular arrays.

Take any whole number between 1 and 999, add the squares of the digits to get a new number. Use a spreadsheet to investigate this sequence.

Learn how to use advanced pasting techniques to create interactive spreadsheets.

Investigate factors and multiples using this interactive Excel spreadsheet. Use the increment buttons for experimentation and feedback.

Using an understanding that 1:2 and 2:3 were good ratios, start with a length and keep reducing it to 2/3 of itself. Each time that took the length under 1/2 they doubled it to get back within range.

Use Excel to investigate digit sums of multiples of three. Can you explain your findings?

Learn how to make a simple table using Excel.

A heap of beads was shared out by a professional bead sharer. Use the information given to find out how many beads there were at the start.

Your school has been left a million pounds in the will of an ex- pupil. What model of investment and spending would you use in order to ensure the best return on the money?

Learn how to use increment buttons and scroll bars to create interactive Excel resources.

The heptathlon is an athletics competition consisting of 7 events. Can you make sense of the scoring system in order to advise a heptathlete on the best way to reach her target?

Use an Excel spreadsheet to investigate differences between four numbers. Which set of start numbers give the longest run before becoming 0 0 0 0?

By tossing a coin one of three princes is chosen to be the next King of Randomia. Does each prince have an equal chance of taking the throne?

A number of useful techniques that can extend your use of Excel.

Use Excel to find sets of three numbers so that the sum of the squares of the first two is equal to the square of the third.

When is 7^n + 3^n a multiple of 10? Use Excel to investigate, and try to explain what you find out.

If you take two integers and look at the difference between the square of each value, there is a nice relationship between the original numbers and that difference. Can you find the pattern using. . . .

I have an unlimited supply of planks, of lengths 7 and 9 units. Putting planks end to end, what total lengths can be achieved? Use Excel to investigate.

Substitute -1, -2 or -3, into an algebraic expression and you'll get three results. Is it possible to tell in advance which of those three will be the largest ?

A ribbon is nailed down with a small amount of slack. What is the largest cube that can pass under the ribbon ?

A plastic funnel is used to pour liquids through narrow apertures. What shape funnel would use the least amount of plastic to manufacture for any specific volume ?

Use Farey sequences to obtain rational approximations to irrational numbers.

It's like 'Peaches Today, Peaches Tomorrow' but interestingly generalized.

However did we manage before calculators? Is there an efficient way to do a square root if you have to do the work yourself?

A fire-fighter needs to fill a bucket of water from the river and take it to a fire. What is the best point on the river bank for the fire-fighter to fill the bucket ?.

What day of the week were you born on? Do you know? Here's a way to find out.

The diagram illustrates the formula: 1 + 3 + 5 + ... + (2n - 1) = n² Use the diagram to show that any odd number is the difference of two squares.

Use an Excel spreadsheet to explore long multiplication.

Use Excel to practise adding and subtracting fractions.

Use an interactive Excel spreadsheet to investigate factors and multiples.

An Excel spreadsheet with an investigation.

What does this number mean ? Which order of 1, 2, 3 and 4 makes the highest value ? Which makes the lowest ?

Use Excel to explore multiplication of fractions.