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Arrays: Multiplication, Division, Fact Families and More!! | Instructions: | Suggested Lessons or Activities: | Special Features: | Other Related Modules and Useful Links:


Arrays: Multiplication, Division, Fact Families and More!!


© R. Mirshahi

Instructions:

  • Click the plus or minus buttons to increase or decrease the number of rows and columns in the array. Watch the multiplication and division facts for the array you have made. Arrays can be used to model multiplication, division and fractions of a set. Use the pen to annotate.

Suggested Lessons or Activities:

  • Model multiplication, division, and fractions of a set.

Here you see how you can find two-fifths of 30 using an array.

FractionOf-aSet.png


  • Show the relationship between the array you make and the multiplication and division facts.
  • Ask the students to click the "eye" button to hide the facts, make an array, write the facts and click the eye again to see if they are right.
  • Use the pencil to show how you can split an array (e.g., 6x5 = (2x5) + (4x5) or 6 rows of 5 is equal to 2 rows of 5 plus 4 rows of 5)
  • Add one row and one column at a time to make square arrays (e.g., 1x1, 2x2, 3x3, 4x4, 5x5, 6x6, 7x7, etc.). Explain why we call the resulting products (1, 4, 9, 16, 25, 36, 49, etc.) squares.
  • This resource is great for finding the factors for some numbers (e.g., 24 can be arranged in 2 rows, 3 rows, 4 rows, etc.) and understanding why certain numbers are considered prime (e.g., 11 can only be arranged in 1 row or 1 column).
  • This array also shows you a mental math strategy when multiplying numbers greater than 10 (e.g., 12x14= 100+20+40+(2x4) = 168). The squares on the grid are coloured differently to show this strategy. See below how you can use this strategy to multiply 2-digit numbers.
Array Subarray for multiplication.PNG
  • This array can also be used to show a growing or shrinking pattern. Add or remove one row or one column at a time and check the products (e.g., if you start with three tiles and add one row or column at a time you will see: 3, 6, 9, 12, 15, ...).

Special Features:

  • Full screen
  • annotation
  • great for interactive whiteboards

Other Related Modules and Useful Links: