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

Our 2008 Advent Calendar has a 'Making Maths' activity for every day in the run-up to Christmas.

All the activities in the 2013 advent calendar are based on the theme of planet earth.

Advent Calendar 2010 - a mathematical game for every day during the run-up to Christmas.

Advent Calendar 2010 - a mathematical game for every day during the run-up to Christmas.

All the activities in this year's primary Advent Calendar have a food or drink theme. Yum yum!

The 2012 primary advent calendar features twenty-four of our posters, one for each day in the run-up to Christmas.

Twenty four games for the run-up to Christmas.

Twenty-four tasks for the run-up to Christmas.

Twenty-four tasks for the run-up to Christmas.

This advent calendar contains twenty-four tasks for the run-up to Christmas, each one encouraging mathematical creativity.

Twenty-four tasks for the run-up to Christmas, each one encouraging you to develop mathematical 'habits of mind'.

Paint a stripe on a cardboard roll. Can you predict what will happen when it is rolled across a sheet of paper?

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. . . .

Bernard Bagnall recommends some primary school problems which use numbers from the environment around us, from clocks to house numbers.

Here is a version of the game 'Happy Families' for you to make and play.

This article for teachers sets out some ideas for introducing children to some of the concepts at the root of mechanics.

Nowadays the calculator is very familiar to many of us. What did people do to save time working out more difficult problems before the calculator existed?

Find out about the five-term project (January 2014 to July 2015) which NRICH is leading in conjunction with Haringey Council, funded by London Schools Excellence Fund.