Second Grade · Math · week 31

Arrays: rows and columns

Build and describe rectangular arrays using rows and columns, and find the total using repeated addition.

An array is objects lined up neatly in rows and columns, like a mini grid -- think of an egg carton or a window with panes. Rows go side to side; columns go up and down.

To find the total in an array, you can add up each row, since every row has the same number of items.

📋 For the teacher
Teach it (10–15 min):
  • Point out arrays around the house: muffin tins, egg cartons, tile floors, window panes -- arrays are everywhere once you start looking.
  • Have them build a small array with real objects (crackers, coins, blocks) in neat rows before counting the total.
  • Emphasize that every row must have the same number of items -- that is what makes it an array and not just a random arrangement.
  • Let them count by adding rows or by skip counting -- both get the same right answer.
Talk about it:
  • What is the difference between a row and a column in an array?
  • Why does every row in an array need to have the same number of items?
  • Can you find a real array somewhere in the house right now?

Mastery looks like: They build an array with equal rows and columns and find the total using repeated addition of the rows.

Common stumbles: Building rows with different numbers of items (not a true array); miscounting when rows are large.

See it visually

Interactive, spoken-aloud tools that show this idea in motion.

MultiplicationEqual groups and arrays make products finally click.try →AdditionSee groups combine — with counters, blocks, and the number line.try →
Homework for this lessonType it, write it with a stylus, or print it for pencil & paper.open →
Records attendance + 15 min of Math for this learner.
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