# Archive of assignments

After the award ceremony of the Dutch national competition in March, the assigment of the previous year is made available on this page. Most of the assignments are available in both Dutch and English. All English assignments are shown on this page. If you would like to view all assignments (1999-current), including those only available in Dutch, go to the Dutch version of this page.

We do not supply answers for the assignments.

### Arrow clocks (2017)

People are made to recognise patterns and structures. Mathematics turns this into a sport. In this assignment simple recipes lead to wonderful images which we call arrow clocks and line.
The challenge for you is to discover the patterns and structures underneath.

A nice set of dice (2016)

A soccer competition is often exciting until the end. Some strange results can occur along the way. For example, if Ajax beats PSV and PSV beats Feyenoord it does not imply that Ajax then beats Feyenoord. It is not unthinkable that Feyenoord still beats Ajax. In this case, which of these three teams is the strongest team remains unclear. During the assignment of Mathematics B-day this year, we examine whether this also occurs when you are rolling dice.

### Around the corner (2015)

In 2015, the assignment was centered around the question whether certain objects can be moved through a 1 meter wide corridor with a right-angled corner in it. In particular, the assignment examines the problem in two dimensions: which two-dimensional mathematical shapes (line segment, rectangle, circle, ...) can be moved through the corridor?

### Lights Out (2014)

The 2014 assignment is about the game 'Lights Out’. The game is played on a grid of five rows by five columns with a total of 25 lights. Some of the lights are switched on at the start of the game. The point of Lights Out, as the name already suggests, is to switch off all the lights. We supply an online version of the applet as well as a downloadable version

### Reflecting on mirrors (2013)

This assignment is about mirrors and light beams. You can't actually see these light beams, but if you want to understand how mirrors work (and work together), you will need to draw these light beams in a sketch or an exact construction. The assignment includes an applet and a set of worksheets. The assignment also requires four square mirror tiles and tape.

### (Cr)easy! Paper strip folding (2012)

Simple strips of folded paper are the key to this task that plunges students into the world of working mathematically. In it, a paper strip is folded several times. Can you predict the pattern that emerges from any given 'folding recipe'? Why are start and end of the pattern always perpendicular? There are 2^n different walking patterns after n folds. All patterns have the same distance between start and end point. Why? This assignment includes an applet (EN).

### The final move (2011)

This assignment is all about games for two players. In particular, it is about games in which probability and luck (for instance, rolling a die) play no part. For example: There are 21 matches on the table. Each turn, a player must remove either 1, 2 or 3 matches. The player who removes the last match loses. What is the best strategy? This assignment includes an Excel file with the TakeAway game, as well as instructions for the game.

### Zig-zag and the anti-periodic (2010)

This assignment is about piecewise linear functions and their graphs. These are mainly examined using a computer. For this, you need to use GeoGebra. We also supply a GeoGebra file.

### How to crash a dot (2009)

In this assignment you will study a game that was invented in the 1970s. It was one of the first computer games. The game is very simple, since computers in those days were very limited in what they could do. The playing board consists of a grid of horizontal and vertical lines. In the game, you move your 'car' from gridpoint to gridpoint. The assignment includes the Excel file Turnracer.

### The snail and bean conundrum (2008)

This assignment has two parts. In the first part, you will study the movement of a special sort of 'snail': snails made of cubical blocks. The second part is inspired by a traditional African game which is usually played using seeds and is known under different names, such as Kalaha, Oware, Wari or Awélé. However, in this assignment we use beans instead of seeds. The assignment uses two Excel files: snail, sowing (instructions).

### Polygons, triangles and capes (2007)

You know them already, of course: triangles, quadrilaterals, pentagons and polygons. The generic name is simple polygon.This Mathematcs B-day assignment is about special closed figures that do not retrace points and figures composed of a finite sequence of straight-line segments: assignment, worksheets, definition list.

### In the hands of time (2006)

This assignment focuses on time as it is shown on a clock face with a small hour hand and a big minute hand. The minute hand moves much faster than the hour hand. Once in a while it takes over the lead from the hour hand. How often in a period of twelve hours do the minute and the hour hand lie exactly on top of each other? At exactly what time does the minute hand overtake the hour hand on the clock above?

### A round mathematics (2003)

This assignment concerns the mathematics that spontaneously emerges in a toy named Tangles. Tangles can be bought at various (online) toy stores.

### Crossing a desert in a jeep (2001)

You are planning a trip through the desert. Your jeep can carry fuel for only 1000 km, and the next petrol station is 3000 km ahead. What is the best way to get across? The final problem of this assignment is a very open problem. The task as a whole is structured in such a way that students will investigate smaller problems first to discuss and develop a strategy that works for the final problem.