Math Background

Using Arrays to Show Multiplication Concepts: When Students Ask

  • What are arrays? Will I ever see arrays in real life?
    Arrays are arrangements of objects in rows and columns. There are many examples of arrays in the classroom, the home, and the community. The exercises on many pages in the math book use arrays; stamps and stickers are packaged in arrays. Floor tiles and bricks are often laid out in arrays.
  • Why do we use arrays to learn multiplication?
    Using different models helps students better understand multiplication. They used equal groups to multiply in their first lesson on multiplication in Grade 3. The equal groups show the relationship between multiplication and repeated addition. This in turn helps students learn different ways to multiply—skip counting, drawing a picture, and using an array. Each row of objects in an array can be seen as an equal group of objects.
  • Will I use arrays for anything else?
    Yes. Arrays are also used in math to show division.
  • Why should I learn about the Commutative Property of Multiplication?
    The Commutative Property of Multiplication states that changing the order of the factors does not change the product. By learning about the Commutative Property of Multiplication, students will discover that they know twice as many facts as they thought they knew! For example, if they know 9 x 5 = 45, then they also know 5 x 9 = 45.
  • Why should I bother learning multiplication, especially if I have a calculator?
    Students will use multiplication in other topics they study in math class, such as geometry and measurement. They will also use multiplication in real life when they are shopping, playing games, or figuring the interest on their savings accounts. They should know that they may not always have a calculator with them, so having their multiplication facts memorized will come in handy!

Houghton Mifflin Math Grade 3