Topic explanation

Standard explanation

A 2x3 matrix has 2 rows, 3 columns. You cannot add a 2x3 to a 3x2. The entry a_{ij} sits in row i, column j (1-based school).

Key points

• row then column
• m x n = rows by columns
• equal: same size + same entries
• rows first
• MATRIX ORDER AND DIMENSIONS: A 2x3 matrix has 2 rows, 3 columns. You cannot add a 2x3 to a 3x2. The entry a_{ij} sits in row i, c
• SIZE: A 2x3 matrix has 2 rows, 3 columns.
• WHAT — MATRIX ORDER AND DIMENSIONS: A 2x3 matrix has 2 rows, 3 columns. You cannot add a 2x3 to a 3x2. The entry a_{ij} sits in row i, c
• WHY — Why it matters: This rule is a separate learning unit inside matrices: shape and types. It can be defined, applied,

Labelled diagram