Julirde, or the “game of the mosque,” is played by boys of the Fulbe ethnic group in West Africa. The Fulbe are mainly cattle herders. They move from place to place looking for feed for their animals. They live in a region that extends from Senegal to Cameroon. Boys help with the cattle while girls have other tasks. This game keeps the boys on their toes and helps them pass the time while the cattle are grazing.
The Fulbe people, also called Fulani in English, have a history going back many centuries. Their ancestors were rulers of several African kingdoms. In the eleventh century many Fulbe converted to the religion of Islam. The word Islam means “peace.” The mosque is the place of prayer for followers of Islam. That explains the name of the game.
Here are the rules of the game as played by the Fulbe boys. They drew their game board in the sand or soil. You may use paper and pencil or a geoboard.
1. Draw a set of dots to form a nine by nine square. Figure 1
2. Draw a closed loop that connects all the dots. You may not retrace a line segment. The loop must go from one dot to another dot in the same row or column. Diagonal lines are not allowed. The loop ends at the starting point.
3. There must be an opening on each of the four sides of the square for people to enter the mosque. The letter E marks each opening in Figure 2
4. If the side of the square has an odd number of dots, the middle dot is not in the game.
9 × 9 square grid of dets
Figure 1
Jurlirude on a9 × 9 grid, with turn symmetry
Figure 2
Source: PaulusGerdes, “Exploring the Game of Jurlirde,” Teaching Children Mathematics.
5 × 5 square grid of dots
Figure 3
5. The game drawing must be symmetrical; that is, it looks the same from all four sides of the square.
The Julirde in Figure 2 seems complicated, doesn’t it? Don’t worry— you will start with simpler versions. Here are some things to look for:
• The loop is closed; it came back to the starting point.
• The loop went through every point except the center point.
• The connecting line either went straight ahead or made a 90° turn.
• No line segment was retraced.
• There is at least one opening on each of the four sides of the mosque.
• The diagram looks the same from all four sides of the square. It has turn symmetry. To check, rotate the page a quarter turn, then another and another, until you are back to the starting position. Notice how every side of the square looks the same.
Let’s start with an easier version of the Julirde game.
• Dot paper. You can buy this at craft or school supply stores. If you don’t have any, use graph paper or lined paper.
• Pencil
• Eraser
1. Draw a 5 × 5 square of dots. Use dot paper, if possible. Otherwise draw the dots on graph paper or lined paper.
2. Draw a small circle around the center dot. That dot is not in the game. Figure 3
3. Draw a closed loop that connects all the dots and leaves an opening on each of four sides.
4. Is your drawing symmetrical—does it look the same from all four sides?
It may take some practice before you get it right. That’s how you learn what works and what doesn’t. Don’t give up!
1. Try to make a Julirde drawing on a 3 × 3 square of dots. Then try a 4 × 4 square. Can you make a drawing that has openings on all four sides? Can you make a drawing that has openings on just two opposite sides?
2. Make a drawing on a 5 × 5 square that is different from the one you already made.
3. Make a Julirde drawing on a 6 × 6 square. You may find that it does not look the same from all four sides. What type of symmetry does it have? If you fold the diagram down the center, does one half match the other half? This is called line symmetry. If your drawing does not have any symmetry, try again. Figure 4
4. Experiment with square grids of different sizes: 7 × 7, 8 × 8, 9 × 9, etc. Are they symmetrical? What type of symmetry do they have?
5. In general, which drawings have turn symmetry? Which have line symmetry?
6. Play the game with a friend.
Jurlirde on a 6 × 6 with line symmestery
Figure 4
