Terminology

 
 Array (an arrangement of objects in rows and columns)

 Columns (the vertical groups in a rectangular array)

 Even number (a whole number whose last digit is 0, 2, 4, 6, or 8)

 Odd number (any number that is not even)

 Repeated addition (e.g., 2 + 2 + 2)

 Rows (the horizontal groups in a rectangular array)

 Tessellation (tiling of a plane using one or more geometric shapes with no overlaps and no gaps)

 Whole number (e.g., 0, 1, 2, 3, …)