An array is an arrangement of objects, pictures, or numbers in columns and rows. In mathematics, they are useful representations of multiplication concepts. For example, 3 x 4 = 12 can be shown in an array of 3 rows and 4 columns equals 12 in total. There are many ways to teach arrays but here are four activities which students really enjoy.
Teaching arrays idea 1: When you ask students to sit on the mat/floor, ask them to sit in arrays. For example, ask students to sit in rows of 5. If you have 29 students, students would be able to sit in 5 rows of 5 with 4 remaining students. This is a great opportunity to explore not only the concept of arrays but the mathematical language. Through discussion of simply sitting on the floor in arrays you can use key words such as: rows, columns, horizontal, vertical, equal, total, left over and remainders. If space on the mat/floor is limited you could achieve the same outcomes by asking students to line up in arrays before entering the classroom.
Teaching arrays idea 2: Play ‘The Array Game’. This simple game has been posted and uploaded many times on various sites. To play the game, students need to work in pairs. Each pair requires 2 dice and each student needs to rule up a 10 by 10 square playing grid on grid paper.
Player 1 roles both dice. Player 1 then decides on the array they will colour on their gird. For example, if player 1 roles a 6 and 4, they may choose to colour a 6 by 4 array or a 4 by 6 array. Then, it is player 2’s turn. Players take it in turns until a player cannot colour an array on their grid because it won’t fit. The other player is then the winner. There are possible variations of this game to incorporate other mathematical concepts. For example, each time a student colours an array they need to record the perimeter and the area of each array.
Teaching arrays idea 3: Create a class array chart. This idea came from a colleague of mine, Jayne Auld. She got large sheets of white paper, stuck them together and created a large array chart. Students then made and stuck on arrays to fill the chart.
Teaching arrays idea 4: Provide students with a range of opened ended questions. These types of questions are my favouite as they encourage students to think in multiple ways. Possible questions might include:
a) What might the missing numbers be? a x b =12. Can you draw all the possible arrays?
b) Jacob, John and Amanda were building a rectangular wall of ice one block thick. They made 36 blocks of snow but couldn’t decide what the dimensions should be. Give them a list of all the possibilities.
c) There are 24 children at a PE lesson. If there are 3 teams all lined up, how many children would there be in each team? Show your solution.
d) The auditorium has 35 rows. Each row seats 13 people. How many people can be seated here?