Helen buys some cakes and some buns for her party. Can you work out how many of each she buys?

Clare Green looks at the role of the calculator in the teaching and learning of primary mathematics.

If I tell you two sides of a right-angled triangle, you can easily work out the third. But what if the angle between the two sides is not a right angle?

Weekly Problem 49 - 2013

What is the value of 2000 + 1999 × 2000?

A game to be played against the computer, or in groups. Pick a 7-digit number. A random digit is generated. What must you subract to remove the digit from your number? the first to zero wins.

Consider these analogies for helping to understand key concepts in calculus.

Can you hit the target functions using a set of input functions and a little calculus and algebra?

If we had 16 light bars which digital numbers could we make? How will you know you've found them all?

Don't get rid of your old calendars! You can get a lot more mathematical mileage out of them before they are thrown away. These activities, using cut up dates from the calendar, provide numbers to. . . .

Try adding together the dates of all the days in one week. Now multiply the first date by 7 and add 21. Can you explain what happens?

Choose any three by three square of dates on a calendar page...

Make a pair of cubes that can be moved to show all the days of the month from the 1st to the 31st.

The pictures on the timetable have been muddled up! Can you help put them back in order?

In this section from a calendar, put a square box around the 1st, 2nd, 8th and 9th. Add all the pairs of numbers. What do you notice about the answers?

The pages of my calendar have got mixed up. Can you sort them out?

Calendars were one of the earliest calculating devices developed by civilizations. Find out about the Mayan calendar in this article.

Resources from Charlie's Science Festival sessions, March 2014

Resources from Charlie's Science Festival session, March 2018

When if ever do you get the right answer if you add two fractions by adding the numerators and adding the denominators?

Can you find rectangles where the value of the area is the same as the value of the perimeter?

Try some throwing activities and see whether you can throw something as far as the Olympic hammer or discus throwers.

Given a sketch of a curve with asymptotes, can you find an appropriate function?

Can you find cubic functions which satisfy each condition?

Can you create random variables satisfying certain conditions?

Can you find any perfect numbers? Read this article to find out more...

Can you work out the equation of the function from its graph?

Can you find equations for cubic curves that have specific features?

Can you find trig graphs to satisfy a variety of conditions?

What graphs can you make by transforming sine, cosine and tangent graphs?

How many ways can you find to put in operation signs (+ - x ÷) to make 100?

Here are a collection of statements to prove, to help you to practise writing out clear mathematical proofs.

Can you generate a set of random results? Can you fool the random simulator?

Can you find a fraction with the following properties?

What length of candy floss can Rita spin from her cylinder of sugar?

How high will a ball taking a million seconds to fall travel?

Weekly Problem 4 - 2012

What fraction of the volume of this can is filled with lemonade?

How do scientists or mathematicians estimate the size of a population of wild animals?

Is it really greener to go on the bus, or to buy local?